[ { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/6qrb6-1bs03", "eprint_id": 37519, "eprint_status": "archive", "datestamp": "2023-08-19 14:41:08", "lastmod": "2023-10-23 17:43:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Butler-M-C", "name": { "family": "Butler", "given": "Mark C." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Sensitivity of force-detected NMR spectroscopy with resonator-induced polarization", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2013 American Physical Society.\nReceived 19 August 2012; published 13 February 2013.\n\n
Published - Butler_2013p064413.pdf
", "abstract": "In the low-temperature regime where the thermal polarization P is of order unity and spin-lattice relaxation is \"frozen out,\" resonator-induced relaxation can be used to polarize a nuclear-spin sample for optimal detection sensitivity. We characterize the potential of resonator-induced polarization for enhancing the sensitivity of nuclear-magnetic-resonance spectroscopy. The sensitivities of two detection schemes are compared, one involving detection of a polarized sample dipole and the other involving detection of spin-noise correlations in an unpolarized sample. In the case where the dominant noise source is instrument noise associated with resonator fluctuations and with detection of the mechanical motion, a simple criterion can be used to compare the two schemes. Polarizing the sample improves sensitivity when P is larger than the signal-to-noise ratio for detection of a fully-polarized spin during a single transient. Even if the instrument noise is decreased to a level near the quantum-mechanical limit, it is larger than spin noise for unpolarized samples containing up to a few tens of nuclei. Under these conditions, spin polarization of order unity would enhance spectroscopic detection sensitivity by an order of magnitude or more. In the limiting case where signal decay is due to resonator-induced dissipation during ideal spin locking, and where resonator fluctuations are the noise source, the only parameter of the spin-resonator system that affects the sensitivity per spin is the ratio of frequency to temperature. A balance between the coupling strength, the noise power, and the signal lifetime causes the cancellation of other parameters from the sensitivity formula. Partial cancellation of parameters, associated with a balance between the same three quantities, occurs more generally when the resonator is both the dominant noise source and the dominant source of signal decay. An intrinsic sensitivity limit exists for resonant detection of coherent spin evolution, due to the fact that the detector causes signal decay by enhancing the spins' spontaneous emission. For a single-spin sample, the quantum-limited signal-to-noise ratio for resonant detection is 1/3. In contrast to the sensitivity, the time required for sample polarization between transients depends strongly on resonator parameters. We discuss resonator design and show that for a torsional resonator, the coupling is optimal when the resonator's magnetization remains aligned with the applied field during the mechanical oscillations.", "date": "2013-02-13", "date_type": "published", "publication": "Physical Review B", "volume": "87", "number": "6", "publisher": "American Physical Society", "pagerange": "Art. No. 064413", "id_number": "CaltechAUTHORS:20130314-111403151", "issn": "1098-0121", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130314-111403151", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevB.87.064413", "primary_object": { "basename": "Butler_2013p064413.pdf", "url": "https://authors.library.caltech.edu/records/6qrb6-1bs03/files/Butler_2013p064413.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Butler, Mark C. and Weitekamp, Daniel P." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2z4z4-ra174", "eprint_id": 29916, "eprint_status": "archive", "datestamp": "2023-08-19 10:14:44", "lastmod": "2023-10-24 22:34:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Butler-M-C", "name": { "family": "Butler", "given": "Mark C." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Resonator-induced dissipation of transverse nuclear-spin signals in cold nanoscale samples", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2012 American Physical Society. Received 17 January 2012; published 9 March 2012.\n\nPublished - Butler2012p17575Phys_Rev_B.pdf
Supplemental Material - README.TXT
Supplemental Material - relaxation_plots.pdf
", "abstract": "The back action of typical macroscopic resonators used for detecting nuclear magnetic resonance can cause a reversible decay of the signal, known as radiation damping. A mechanical resonator that is strongly coupled to a microscopic sample can in addition induce an irreversible dissipation of the nuclear-spin signal, distinct from radiation damping. We provide a theoretical description of resonator-induced transverse relaxation that is valid for samples of a few nuclear spins in the low-temperature regime, where quantum fluctuations play a significant role in the relaxation process, as well as for larger samples and at higher temperatures. Transverse relaxation during free evolution and during spin locking are analyzed, and simulations of relaxation in example systems are presented. In the case where an isolated spin 1/2 interacts with the resonator, transverse relaxation is exponential during free evolution, and the time constant for the relaxation is T_2=2/R_h, where R_h is the rate constant governing the exchange of quanta between the resonator and the spin. For a system of multiple spins, the time scale of transverse relaxation during free evolution depends on the spin Hamiltonian, which can modify the relaxation process through the following effects: (1) changes in the structure of the spin-spin correlations present in the energy eigenstates, which affect the rates at which these states emit and absorb energy, (2) frequency shifts that modify emission and absorption rates within a degenerate manifold by splitting the energy degeneracy and thus suppressing the development of resonator-induced correlations within the manifold, and (3) frequency shifts that introduce a difference between the oscillation frequencies of single-quantum coherences \u03c1_(ab) and \u03c1_(cd) and average to zero the transfers between them. This averaging guarantees that the spin transitions responsible for the coupling between \u03c1_(ab) and \u03c1_(cd) cause irreversible loss of order rather than a reversible interconversion of the coherences. In systems of a few spins, transverse relaxation is accelerated by a dipolar Hamiltonian that is either the dominant term in the internal spin Hamiltonian or a weak perturbation to the chemical-shift Hamiltonian. A pure chemical-shift Hamiltonian yields exponential relaxation with T_2=2/R_h in the case where the Larmor frequencies of the spins are distinct and sufficiently widely spaced. During spin locking with a nutation frequency fast enough to average the evolution under the internal spin Hamiltonian but not the interactions occurring during the correlation time of the resonator, relaxation of the spin-locked component is exponential with time constant T_(1\u03c1)=2/R_h.", "date": "2012-03-09", "date_type": "published", "publication": "Physical Review B", "volume": "85", "number": "10", "publisher": "American Physical Society", "pagerange": "Art. No. 104405", "id_number": "CaltechAUTHORS:20120330-134535697", "issn": "1098-0121", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120330-134535697", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevB.85.104405", "primary_object": { "basename": "Butler2012p17575Phys_Rev_B.pdf", "url": "https://authors.library.caltech.edu/records/2z4z4-ra174/files/Butler2012p17575Phys_Rev_B.pdf" }, "related_objects": [ { "basename": "README.TXT", "url": "https://authors.library.caltech.edu/records/2z4z4-ra174/files/README.TXT" }, { "basename": "relaxation_plots.pdf", "url": "https://authors.library.caltech.edu/records/2z4z4-ra174/files/relaxation_plots.pdf" } ], "resource_type": "article", "pub_year": "2012", "author_list": "Butler, Mark C. and Weitekamp, Daniel P." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/dqsbk-86d33", "eprint_id": 28681, "eprint_status": "archive", "datestamp": "2023-08-19 08:53:59", "lastmod": "2023-10-24 18:04:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Butler-M-C", "name": { "family": "Butler", "given": "Mark C." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Polarization of nuclear spins by a cold nanoscale resonator", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2011 American Physical Society. Received 14 July 2011; published 6 December 2011.\n\nPublished - Butler2011p16651Phys_Rev_A.pdf
Supplemental Material - README.TXT
Supplemental Material - relaxation_plots.pdf
", "abstract": "A cold nanoscale resonator coupled to a system of nuclear spins can induce spin relaxation. In the low-temperature limit where spin-lattice interactions are \"frozen out,\" spontaneous emission by nuclear spins into a resonant mechanical mode can become the dominant mechanism for cooling the spins to thermal equilibrium with their environment. We provide a theoretical framework for the study of resonator-induced cooling of nuclear spins in this low-temperature regime. Relaxation equations are derived from first principles, in the limit where energy donated by the spins to the resonator is quickly dissipated into the cold bath that damps it. A physical interpretation of the processes contributing to spin polarization is given. For a system of spins that have identical couplings to the resonator, the interaction Hamiltonian conserves spin angular momentum, and the resonator cannot relax the spins to thermal equilibrium unless this symmetry is broken by the spin Hamiltonian. The mechanism by which such a spin system becomes \"trapped\" away from thermal equilibrium can be visualized using a semiclassical model, which shows how an indirect spin-spin interaction arises from the coupling of multiple spins to one resonator. The internal spin Hamiltonian can affect the polarization process in two ways: (1) By modifying the structure of the spin-spin correlations in the energy eigenstates, and (2) by splitting the degeneracy within a manifold of energy eigenstates, so that zero-frequency off-diagonal terms in the density matrix are converted to oscillating coherences. Shifting the frequencies of these coherences sufficiently far from zero suppresses the development of resonator-induced correlations within the manifold during polarization from a totally disordered state. Modification of the spin-spin correlations by means of either mechanism affects the strength of the fluctuating spin dipole that drives the resonator. In the case where product states can be chosen as energy eigenstates, spontaneous emission from eigenstate populations into the resonant mode can be interpreted as independent emission by individual spins, and the spins relax exponentially to thermal equilibrium if the development of resonator-induced correlations is suppressed. When the spin Hamiltonian includes a significant contribution from the homonuclear dipolar coupling, the energy eigenstates entail a correlation specific to the coupling network. Simulations of dipole-dipole coupled systems of up to five spins suggest that these systems contain weakly emitting eigenstates that can trap a fraction of the population for time periods \u226b100/R_0, where R_0 is the rate constant for resonator-enhanced spontaneous emission by a single spin 1/2. Much of the polarization, however, relaxes with rates comparable to R_0. A distribution of characteristic high-field chemical shifts tends to increase the relaxation rates of weakly emitting states, enabling transitions to states that can quickly relax to thermal equilibrium. The theoretical framework presented in this paper is illustrated with discussions of spin polarization in the contexts of force-detected nuclear-magnetic-resonance spectroscopy and magnetic-resonance force microscopy.", "date": "2011-12-06", "date_type": "published", "publication": "Physical Review A", "volume": "84", "number": "6", "publisher": "American Physical Society", "pagerange": "Art. No. 063407", "id_number": "CaltechAUTHORS:20120105-140856686", "issn": "1050-2947", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120105-140856686", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevA.84.063407", "primary_object": { "basename": "Butler2011p16651Phys_Rev_A.pdf", "url": "https://authors.library.caltech.edu/records/dqsbk-86d33/files/Butler2011p16651Phys_Rev_A.pdf" }, "related_objects": [ { "basename": "README.TXT", "url": "https://authors.library.caltech.edu/records/dqsbk-86d33/files/README.TXT" }, { "basename": "relaxation_plots.pdf", "url": "https://authors.library.caltech.edu/records/dqsbk-86d33/files/relaxation_plots.pdf" } ], "resource_type": "article", "pub_year": "2011", "author_list": "Butler, Mark C. and Weitekamp, Daniel P." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/r4jkm-wtw44", "eprint_id": 27661, "eprint_status": "archive", "datestamp": "2023-08-19 08:22:23", "lastmod": "2023-10-24 17:19:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Norton-V-A", "name": { "family": "Norton", "given": "Valerie A." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Communication: Partial polarization transfer for single-scan\n spectroscopy and imaging", "ispublished": "pub", "full_text_status": "public", "keywords": "electron spin polarisation, nuclear magnetic resonance, nuclear spin-lattice relaxation", "note": "\u00a9 2011 American Institute of Physics. Received 11 August 2011; accepted 28 September 2011; published online 13 October 2011.\n\nPublished - Norton2011p16162J_Chem_Phys.pdf
", "abstract": "A method is presented to partially transfer nuclear spin polarization from one isotope S to another isotope I by the way of heteronuclear spin couplings, while minimizing the loss of spin order to other degrees of freedom. The desired I spin polarization to be detected is a design parameter, while the sequence of pulses at the two Larmor frequencies is optimized to store the greatest unused S spin longitudinal polarization for subsequent use. The unitary evolution for the case of I_NS spin systems illustrates the potentially ideal efficiency of this strategy, which is of particular interest when the spin-lattice relaxation time of S greatly exceeds that of I. Explicit timing and pulses are tabulated for the cases for which M \u2264 10 partial transfers each result in equal final polarization of 1/M or more compared to the final I polarization expected in a single transfer for N = 1, 2, or 3 I spins. Advantages for the ratiometric study of reacting molecules and hyperpolarized initial conditions are outlined.", "date": "2011-10-14", "date_type": "published", "publication": "Journal of Chemical Physics", "volume": "135", "number": "14", "publisher": "American Institute of Physics", "pagerange": "Art. No. 141107", "id_number": "CaltechAUTHORS:20111108-072024737", "issn": "0021-9606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111108-072024737", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.3652965", "primary_object": { "basename": "Norton2011p16162J_Chem_Phys.pdf", "url": "https://authors.library.caltech.edu/records/r4jkm-wtw44/files/Norton2011p16162J_Chem_Phys.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Norton, Valerie A. and Weitekamp, Daniel P." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/99b9h-z0s79", "eprint_id": 20739, "eprint_status": "archive", "datestamp": "2023-08-19 04:06:42", "lastmod": "2023-10-20 23:23:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Butler-M-C", "name": { "family": "Butler", "given": "Mark C." } }, { "id": "Norton-V-A", "name": { "family": "Norton", "given": "Valerie A." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Nanoscale Torsional Resonator for Polarization and Spectroscopy of Nuclear Spins", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2010 The American Physical Society.\nReceived 26 March 2010; published 19 October 2010.\n\nPublished - Butler2010p11749Phys_Rev_Lett.pdf
", "abstract": "We propose a torsional resonator that couples to the transverse spin dipole of an attached sample. The absence of relative motion eliminates a source of friction that would otherwise hinder nanoscale implementation. Enhanced spontaneous emission induced by the resonator relaxes the longitudinal spin dipole at a rate of ~1\u2009\u2009s^(-1) in the low-temperature limit. With signal averaging, single-proton magnetic resonance spectroscopy appears feasible at ~10\u2009\u2009mK and a high magnetic field, while single-shot sensitivity is practical for samples with at least tens of protons in a volume of ~5\u2009\u2009nm^3.", "date": "2010-10-19", "date_type": "published", "publication": "Physical Review Letters", "volume": "105", "number": "17", "publisher": "American Physical Society", "pagerange": "Art. No. 177601", "id_number": "CaltechAUTHORS:20101110-095440773", "issn": "0031-9007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101110-095440773", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevLett.105.177601", "primary_object": { "basename": "Butler2010p11749Phys_Rev_Lett.pdf", "url": "https://authors.library.caltech.edu/records/99b9h-z0s79/files/Butler2010p11749Phys_Rev_Lett.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Butler, Mark C.; Norton, Valerie A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8rp1d-y6g11", "eprint_id": 19068, "eprint_status": "archive", "datestamp": "2023-08-22 00:11:19", "lastmod": "2023-10-20 19:20:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pfeilsticker-J-A", "name": { "family": "Pfeilsticker", "given": "Jessica A." } }, { "id": "Ollerenshaw-J-E", "name": { "family": "Ollerenshaw", "given": "Jason E." } }, { "id": "Norton-V-A", "name": { "family": "Norton", "given": "Valerie A." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "A selective ^(15)N-to-^1H polarization transfer sequence for more sensitive detection of ^(15)N-choline", "ispublished": "pub", "full_text_status": "restricted", "keywords": "INEPT; PASADENA; ^(15)N-choline; Hyperpolarization; Selective coherence transfer; REBURP", "note": "\u00a9 2010 Elsevier.\n\nReceived 28 July 2009; revised 17 March 2010. Available online 27 April 2010. \n\nThis work was supported by the Beckman Institute pilot program,\n''Spin-Polarized Molecules for Structural and Systems Biology\".\nJEO was supported by a Postdoctoral Fellowship from the\nNatural Sciences and Engineering Research Council of Canada.", "abstract": "The sensitivity and information content of heteronuclear nuclear magnetic resonance is frequently optimized by transferring spin order of spectroscopic interest to the isotope of highest detection sensitivity prior to observation. This strategy is extended to ^(15)N-choline using the scalar couplings to transfer polarization from ^(15)N to choline's nine methyl ^1H spins in high field. A theoretical analysis of a sequence using nonselective pulses shows that the optimal efficiency of this transfer is decreased by 62% as the result of competing ^(15)N\u2013^1H couplings involving choline's four methylene protons. We have therefore incorporated a frequency-selective pulse to support evolution of only the ^(15)N\u2013methyl ^1H coupling during the transfer period. This sequence provides a 52% sensitivity enhancement over the nonselective version in in vitro experiments on a sample of thermally polarized ^(15)N-choline in D_2O. Further, the ^(15)N T_1 of choline in D_2O was measured to be 217 \u00b1 38 s, the ^(15)N\u2013methyl ^1H coupling constant was found to be 0.817 \u00b1 0.001 Hz, and the larger of choline's two ^(15)N\u2013methylene ^1H coupling constants was found to be 3.64 \u00b1 0.01 Hz. Possible improvements and applications to in vivo experiments using long-lived hyperpolarized heteronuclear spin order are discussed.", "date": "2010-07", "date_type": "published", "publication": "Journal of Magnetic Resonance", "volume": "205", "number": "1", "publisher": "Elsevier", "pagerange": "125-129", "id_number": "CaltechAUTHORS:20100715-093443660", "issn": "1090-7807", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100715-093443660", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Beckman Institute pilot program" }, { "agency": "Natural Sciences and Engineering Research Council of Canada Postdoctoral Fellowship" } ] }, "doi": "10.1016/j.jmr.2010.04.010", "resource_type": "article", "pub_year": "2010", "author_list": "Pfeilsticker, Jessica A.; Ollerenshaw, Jason E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/k5127-hy861", "eprint_id": 15042, "eprint_status": "archive", "datestamp": "2023-08-20 01:10:33", "lastmod": "2023-10-18 20:28:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chekmenev-E-Y", "name": { "family": "Chekmenev", "given": "Eduard Y." } }, { "id": "Norton-V-A", "name": { "family": "Norton", "given": "Valerie A." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } }, { "id": "Bhattacharya-P-K", "name": { "family": "Bhattacharya", "given": "Pratip K." } } ] }, "title": "Hyperpolarized ^1H NMR employing low \u03b3 nucleus for spin polarization storage", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2009 American Chemical Society. ACS AuthorChoice. \n\nPublication Date (Web): February 16, 2009. Received December 9, 2008. \n\nWe thank Drs. Brian D. Ross and William H. Perman and the following for funding: NIH 1K99CA134749-01, R01 CA 122513, 1R21 CA118509, Rudi Schulte Research Institute, James G. Boswell Fellowship, AHA, American Brain Tumor Association, Beckman Institute, Tobacco Related Disease Research Program 16KT-0044, Prevent Cancer Foundation.\n\nPublished - Chekmenev2009p1672J_Am_Chem_Soc.pdf
", "abstract": "The PASADENA (parahydrogen and synthesis allow dramatically enhanced nuclear alignment)(1, 2) and DNP (Dynamic Nuclear Polarization)(3) methods efficiently hyperpolarize biologically relevant nuclei such as 1^H, (31)^P, (13)^C, (15)^N achieving signal enhancement by a factor of ~ 100000 on currently utilized MRI scanners. Recently, many groups have demonstrated the utility of hyperpolarized MR in biological systems using hyperpolarized (13)^C biomarkers with a relatively long spin lattice relaxation time T_1 on the order of tens of seconds.(4-7) Moreover, hyperpolarized (15)^N for biomedical MR has been proposed due to even longer spin lattice relaxations times.(8) An additional increase of up to tens of minutes in the lifetime of hyperpolarized agent in vivo could be achieved by using the singlet states of low gamma (\u03b3) nuclei.(9) However, as NMR receptivity scales as \u03b3^3 for spin 1/2 nuclei, direct NMR detection of low \u03b3 nuclei results in a lower signal-to-noise ratio compared to proton detection. While protons are better nuclei for detection, short spin lattice relaxation times prevent direct 1^H hyperpolarized MR in biomedical applications.", "date": "2009-03-11", "date_type": "published", "publication": "Journal of the American Chemical Society", "volume": "131", "number": "9", "publisher": "American Chemical Society", "pagerange": "3164-3165", "id_number": "CaltechAUTHORS:20090814-132951758", "issn": "0002-7863", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090814-132951758", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NIH", "grant_number": "1K99CA134749-01" }, { "agency": "NIH", "grant_number": "R01 CA 122513" }, { "agency": "NIH", "grant_number": "1R21 CA118509" }, { "agency": "Rudi Schulte Research Institute" }, { "agency": "James G. Boswell Fellowship" }, { "agency": "American Brain Tumor Association" }, { "agency": "Caltech Beckman Institute" }, { "agency": "California Tobacco Related Disease Research Program", "grant_number": "16KT-0044" }, { "agency": "Prevent Cancer Foundation" } ] }, "doi": "10.1021/ja809634u", "pmcid": "PMC2662390", "primary_object": { "basename": "Chekmenev2009p1672J_Am_Chem_Soc.pdf", "url": "https://authors.library.caltech.edu/records/k5127-hy861/files/Chekmenev2009p1672J_Am_Chem_Soc.pdf" }, "resource_type": "article", "pub_year": "2009", "author_list": "Chekmenev, Eduard Y.; Norton, Valerie A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1n4md-z6677", "eprint_id": 13017, "eprint_status": "archive", "datestamp": "2023-08-22 13:55:29", "lastmod": "2023-10-17 21:42:50", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kempf-J-G", "name": { "family": "Kempf", "given": "James G." } }, { "id": "Miller-M-A", "name": { "family": "Miller", "given": "Michael A." }, "orcid": "0000-0002-3964-9312" }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Imaging quantum confinement with optical and POWER (perturbations observed with enhanced resolution) NMR", "ispublished": "pub", "full_text_status": "public", "keywords": "GaAs; hyperfine or Knight shift; Stark effect; H-band photoluminescence", "note": "\u00a9 2008 by The National Academy of Sciences of the USA. \n\nEdited by Alexander Pines, University of California, Berkeley, CA, and approved November 11, 2008 (received for review July 7, 2008). This article is a PNAS Direct Submission. Published online before print December 22, 2008, doi: 10.1073/pnas.0806563106 \n\nWe thank Frank Grunthaner of the National Aeronautics and Space Administration Jet Propulsion Laboratory for providing the sample, Doran Smith of the U.S. Army Research Laboratory for the Schr\u00f6dinger\u2013Poisson solver used to calculate the interfacial E field, and Lou Madsen of Virginia Tech for critical reading of the manuscript. This work was supported by National Science Foundation Grant CHE-9612226. \n\nAuthor contributions: J.G.K., M.A.M., and D.P.W. designed research; J.G.K. and M.A.M. performed research; J.G.K. and M.A.M. analyzed data; and J.G.K. and D.P.W. wrote the paper. \n\nThe authors declare no conflict of interest. \n\nThis article contains supporting information online at www.pnas.org/cgi/content/full/0806563106/DCSupplemental.\n\nPublished - KEMpnas08.pdf
Supplemental Material - KEMpnas08supp.pdf
", "abstract": "The nanoscale distributions of electron density and electric fields in GaAs semiconductor devices are displayed with NMR experiments. The spectra are sensitive to the changes to the nuclear-spin Hamiltonian that are induced by perturbations delivered in synchrony with a line-narrowing pulse sequence. This POWER (perturbations observed with enhanced resolution) method enhanced resolution up to 103-fold, revealing the distribution of perturbations over nuclear sites. Combining this method with optical NMR, we imaged quantum-confined electron density in an individual AlGaAs/GaAs heterojunction via hyperfine shifts. Fits to the coherent evolution and relaxation of nuclei within a hydrogenic state established one-to-one correspondence of radial position to frequency. Further experiments displayed the distribution of photo-induced electric field within the same states via a quadrupolar Stark effect. These unprecedented high-resolution distributions discriminate between competing models for the luminescence and support an excitonic state, perturbed by the interface, as the dominant source of the magnetically modulated luminescence.", "date": "2008-12-23", "date_type": "published", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "volume": "105", "number": "51", "publisher": "National Academy of Sciences", "pagerange": "20124-20129", "id_number": "CaltechAUTHORS:KEMpnas08", "issn": "0027-8424", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:KEMpnas08", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CHE-9612226" } ] }, "doi": "10.1073/pnas.0806563106", "pmcid": "PMC2629273", "primary_object": { "basename": "KEMpnas08.pdf", "url": "https://authors.library.caltech.edu/records/1n4md-z6677/files/KEMpnas08.pdf" }, "related_objects": [ { "basename": "KEMpnas08supp.pdf", "url": "https://authors.library.caltech.edu/records/1n4md-z6677/files/KEMpnas08supp.pdf" } ], "resource_type": "article", "pub_year": "2008", "author_list": "Kempf, James G.; Miller, Michael A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/dfjz4-g2e56", "eprint_id": 10843, "eprint_status": "archive", "datestamp": "2023-08-22 11:55:31", "lastmod": "2023-10-16 23:08:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kempf-J-G", "name": { "family": "Kempf", "given": "J. G." } }, { "id": "Marohn-J-A", "name": { "family": "Marohn", "given": "J. A." } }, { "id": "Carson-P-J", "name": { "family": "Carson", "given": "P. J." } }, { "id": "Shykind-D-A", "name": { "family": "Shykind", "given": "D. A." } }, { "id": "Hwang-J-Y", "name": { "family": "Hwang", "given": "J. Y." } }, { "id": "Miller-M-A", "name": { "family": "Miller", "given": "M. A." }, "orcid": "0000-0002-3964-9312" }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } } ] }, "title": "An optical NMR spectrometer for Larmor-beat detection and high-resolution POWER NMR", "ispublished": "pub", "full_text_status": "public", "keywords": "aluminum compounds, gallium arsenide, III-V semiconductors, NMR line breadth, NMR spectroscopy, photoluminescence, semiconductor epitaxial layers, semiconductor heterojunctions", "note": "\u00a92008 American Institute of Physics. \n\nReceived 22 March 2008; accepted 3 May 2008; published 11 June 2008. \n\nWe thank A. Ksendov, J. Liu, and F. Grunthaner of the NASA Jet Propulsion Laboratory Center for Space Microelectronics for providing the sample and preliminary PL characterization, and L. Burnett and A. Perry for cryogenics advice. This work was supported by the NSF Program in Materials Synthesis and Processing (Grant No. CHE-9612226) and by NASA through the Caltech President's Fund.", "abstract": "Optical nuclear magnetic resonance (ONMR) is a powerful probe of electronic properties in III-V semiconductors. Larmor-beat detection (LBD) is a sensitivity optimized, time-domain NMR version of optical detection based on the Hanle effect. Combining LBD ONMR with the line-narrowing method of POWER (perturbations observed with enhanced resolution) NMR further enables atomically detailed views of local electronic features in III-Vs. POWER NMR spectra display the distribution of resonance shifts or line splittings introduced by a perturbation, such as optical excitation or application of an electric field, that is synchronized with a NMR multiple-pulse time-suspension sequence. Meanwhile, ONMR provides the requisite sensitivity and spatial selectivity to isolate local signals within macroscopic samples. Optical NMR, LBD, and the POWER method each introduce unique demands on instrumentation. Here, we detail the design and implementation of our system, including cryogenic, optical, and radio-frequency components. The result is a flexible, low-cost system with important applications in semiconductor electronics and spin physics. We also demonstrate the performance of our systems with high-resolution ONMR spectra of an epitaxial AlGaAs/GaAs heterojunction. NMR linewidths down to 4.1 Hz full width at half maximum were obtained, a 10^3-fold resolution enhancement relative any previous optically detected NMR experiment.", "date": "2008-06-01", "date_type": "published", "publication": "Review of Scientific Instruments", "volume": "79", "number": "6", "publisher": "Review of Scientific Instruments", "pagerange": "Art. No. 063904", "id_number": "CaltechAUTHORS:KEMrsi08", "issn": "0034-6748", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:KEMrsi08", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.2936257", "primary_object": { "basename": "KEMrsi08.pdf", "url": "https://authors.library.caltech.edu/records/dfjz4-g2e56/files/KEMrsi08.pdf" }, "resource_type": "article", "pub_year": "2008", "author_list": "Kempf, J. G.; Marohn, J. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/eqdh5-gpr48", "eprint_id": 79135, "eprint_status": "archive", "datestamp": "2023-08-19 22:45:21", "lastmod": "2023-10-26 14:37:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chekmenev-E-Y", "name": { "family": "Chekmenev", "given": "Eduard Y." } }, { "id": "Chow-Siu-Kei", "name": { "family": "Chow", "given": "Siu-Kei" } }, { "id": "Tofan-D", "name": { "family": "Tofan", "given": "Daniel" } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } }, { "id": "Ross-B-D", "name": { "family": "Ross", "given": "Brian D." } }, { "id": "Bhattacharya-P-K", "name": { "family": "Bhattacharya", "given": "Pratip K." } } ] }, "title": "Fluorine-19 NMR Chemical Shift Probes Molecular Binding to Lipid Membranes", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2008 American Chemical Society. \n\nReceived 23 January 2008. Published online 19 April 2008. Published in print 1 May 2008. \n\nWe thankfully acknowledge funding from the Tobacco Related Disease Research Program New Investigator Grant 16KT-0044, NIH 1R21 CA118509, NIH R01 CA 122513, the Rudi Schulte Research Institute (RSRI) (B.D.R., E.Y.C.), the James G. Boswell Fellowship (E.Y.C.), the American Heart Association (P.B., S.K.C.), the American Brain Tumor Association (P.B.), the Beckman Institute Pilot Program: \"Spin Polarized Molecules for Structural and Systems Biology\" (D.P.W.), the Cancer Research and Prevention Foundation (E.Y.C.), and the SURF program at Caltech (D.T.). We thank Dr. Sonjong Hwang for providing convenient access to the 11.7 T Bruker Avance solid-state NMR facility at Caltech.", "abstract": "The binding of amphiphilic molecules to lipid bilayers is followed by ^(19)F NMR using chemical shift and line shape differences between the solution and membrane-tethered states of \u2212CF_3 and \u2212CHF_2 groups. A chemical shift separation of 1.6 ppm combined with a high natural abundance and high sensitivity of ^(19)F nuclei offers an advantage of using ^(19)F NMR spectroscopy as an efficient tool for rapid time-resolved screening of pharmaceuticals for membrane binding. We illustrate the approach with molecules containing both fluorinated tails and an acrylate moiety, resolving the signals of molecules in solution from those bound to synthetic imyristoylphosphatidylcholine bilayers both with and without magic angle sample spinning. The potential in vitro and in vivo biomedical applications are outlined. The presented method is applicable with the conventional NMR equipment, magnetic fields of several Tesla, stationary samples, and natural abundance isotopes.", "date": "2008-05-22", "date_type": "published", "publication": "Journal of Physical Chemistry B", "volume": "112", "number": "20", "publisher": "American Chemical Society", "pagerange": "6285-6287", "id_number": "CaltechAUTHORS:20170717-151917105", "issn": "1520-6106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170717-151917105", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "California Tobacco-Related Disease Research Program", "grant_number": "16KT-0044" }, { "agency": "NIH", "grant_number": "1R21 CA118509" }, { "agency": "NIH", "grant_number": "R01 CA 122513" }, { "agency": "Rudi Schulte Research Institute" }, { "agency": "James G. Boswell Fellowship" }, { "agency": "American Heart Association" }, { "agency": "American Brain Tumor Association" }, { "agency": "Caltech Beckman Institute" }, { "agency": "Cancer Research and Prevention Foundation" }, { "agency": "Caltech Summer Undergraduate Research Fellowship (SURF)" } ] }, "doi": "10.1021/jp800646k", "resource_type": "article", "pub_year": "2008", "author_list": "Chekmenev, Eduard Y.; Chow, Siu-Kei; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z0t7z-1rj14", "eprint_id": 77418, "eprint_status": "archive", "datestamp": "2023-08-19 22:29:12", "lastmod": "2023-10-25 23:01:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chekmenev-E-Y", "name": { "family": "Chekmenev", "given": "Eduard Y." } }, { "id": "H\u00f6vener-J-B", "name": { "family": "H\u00f6vener", "given": "Jan" } }, { "id": "Norton-V-A", "name": { "family": "Norton", "given": "Valerie A." } }, { "id": "Harris-K-C", "name": { "family": "Harris", "given": "Kent" } }, { "id": "Batchelder-L-S", "name": { "family": "Batchelder", "given": "Lynne S." } }, { "id": "Bhattacharya-P-K", "name": { "family": "Bhattacharya", "given": "Pratip" } }, { "id": "Ross-B-D", "name": { "family": "Ross", "given": "Brian D." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "PASADENA Hyperpolarization of Succinic Acid for MRI and NMR Spectroscopy", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2008 American Chemical Society. \n\nReceived November 7, 2007. Publication Date (Web): March 12, 2008. \n\nWe would like to thank Rudi Schulte Research Institute (RSRI), NIH 1R21 CA118509, NCI, James G. Boswell Fellowship, American Heart Association, American Brain Tumor Association, Beckman Institute Pilot Program (California Institute of Technology), Dr. William Opel for support of the PASADENA program at HMRI, and Dr. Keiko Kanamori (HMRI). We also thank Dr. Scott Ross for providing convenient access to a 14T Varian solution NMR spectrometer at Caltech. The PASADENA polarizer was provided under loan agreement between HMRI and GE Healthcare established by Dr. Klaes Golman, Ms. Marivi Mendizabal, and Dr. J.-H. Ardenkjaer-Larsen.\n\nAccepted Version - nihms96928.pdf
", "abstract": "We use the PASADENA (parahydrogen and synthesis allow dramatically enhanced nuclear alignment) method to achieve ^(13)C polarization of \u223c20% in seconds in 1-^(13)C-succinic-d_2 acid. The high-field ^(13)C multiplets are observed as a function of pH, and the line broadening of C1 is pronounced in the region of the pK values. The ^2J_(CH), ^3J_(CH), and ^3J_(HH) couplings needed for spin order transfer vary with pH and are best resolved at low pH leading to our use of pH \u223c3 for both the molecular addition of parahydrogen to 1-^(13)C-fumaric acid-d_2 and the subsequent transfer of spin order from the nascent protons to C1 of the succinic acid product. The methods described here may generalize to hyperpolarization of other carboxylic acids. The C1 spin\u2212lattice relaxation time at neutral pH and 4.7 T is measured as 27 s in H_2O and 56 s in D_2O. Together with known rates of succinate uptake in kidneys, this allows an estimate of the prospects for the molecular spectroscopy of metabolism.", "date": "2008-04-02", "date_type": "published", "publication": "Journal of the American Chemical Society", "volume": "130", "number": "13", "publisher": "American Chemical Society", "pagerange": "4212-4213", "id_number": "CaltechAUTHORS:20170512-131816890", "issn": "0002-7863", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170512-131816890", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Rudi Schulte Research Institute" }, { "agency": "NIH", "grant_number": "1R21 CA118509" }, { "agency": "National Cancer Institute" }, { "agency": "James G. Boswell Fellowship" }, { "agency": "American Heart Association" }, { "agency": "American Brain Tumor Association" }, { "agency": "Caltech Beckman Institute" }, { "agency": "NIH" } ] }, "doi": "10.1021/ja7101218", "pmcid": "PMC2662769", "primary_object": { "basename": "nihms96928.pdf", "url": "https://authors.library.caltech.edu/records/z0t7z-1rj14/files/nihms96928.pdf" }, "resource_type": "article", "pub_year": "2008", "author_list": "Chekmenev, Eduard Y.; H\u00f6vener, Jan; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/16msr-q1v92", "eprint_id": 1134, "eprint_status": "archive", "datestamp": "2023-08-22 02:19:42", "lastmod": "2023-10-13 22:38:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Madsen-L-A", "name": { "family": "Madsen", "given": "L. A." } }, { "id": "Leskowitz-G-M", "name": { "family": "Leskowitz", "given": "G. M." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } } ] }, "title": "Observation of force-detected nuclear magnetic resonance in a homogeneous field", "ispublished": "pub", "full_text_status": "public", "keywords": "BOOMERANG spectrometry", "note": "\u00a9 2004 by the National Academy of Sciences. \n\nCommunicated by John D. Roberts, California Institute of Technology, Pasadena, CA, July 19, 2004 (received for review May 29, 2003). Published online before print August 23, 2004, 10.1073/pnas.0405232101 \n\nThis research was performed for the Center for Space Microelectronics Technology, Jet Propulsion Laboratory, California Institute of Technology, and was sponsored by the National Aeronautics and Space Administration, Office of Space Science.\n\nPublished - MADpnas04.pdf
", "abstract": "We report the experimental realization of BOOMERANG (better observation of magnetization, enhanced resolution, and no gradient), a sensitive and general method of magnetic resonance. The prototype millimeter-scale NMR spectrometer shows signal and noise levels in agreement with the design principles. We present H-1 and F-19 NMR in both solid and liquid samples, including time-domain Fourier transform NMR spectroscopy, multiple-pulse echoes, and heteronuclear J spectroscopy. By measuring a H-1-F-19 J coupling, this last experiment accomplishes chemically specific spectroscopy with force-detected NMR. In BOOMERANG, an assembly of permanent magnets provides a homogeneous field throughout the sample, while a harmonically suspended part of the assembly, a detector, is mechanically driven by spin-dependent forces. By placing the sample in a homogeneous field, signal dephasing by diffusion in a field gradient is made negligible, enabling application to liquids, in contrast to other force-detection methods. The design appears readily scalable to \u00b5m-scale samples where it should have sensitivity advantages over inductive detection with microcoils and where it holds great promise for application of magnetic resonance in biology, chemistry, physics, and surface science. We briefly discuss extensions of the BOOMERANG method to the \u00b5m and nm scales.", "date": "2004-08-31", "date_type": "published", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "volume": "101", "number": "35", "publisher": "National Academy of Sciences", "pagerange": "12804-12808", "id_number": "CaltechAUTHORS:MADpnas04", "issn": "0027-8424", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:MADpnas04", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1073/pnas.0405232101", "pmcid": "PMC516476", "primary_object": { "basename": "MADpnas04.pdf", "url": "https://authors.library.caltech.edu/records/16msr-q1v92/files/MADpnas04.pdf" }, "resource_type": "article", "pub_year": "2004", "author_list": "Madsen, L. A.; Leskowitz, G. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/c2049-tvp48", "eprint_id": 75774, "eprint_status": "archive", "datestamp": "2023-08-19 08:35:11", "lastmod": "2023-10-25 15:17:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Carson-P-J", "name": { "family": "Carson", "given": "Paul J." } }, { "id": "Bowers-C-R", "name": { "family": "Bowers", "given": "C. Russell" } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "The PASADENA Effect at a Solid Surface: High-Sensitivity Nuclear Magnetic Resonance of Hydrogen Chemisorption", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2001 American Chemical Society. \n\nReceived 2 March 2001. Published online 3 November 2001. Published in print 1 November 2001.", "abstract": "The use of parahydrogen as a high-sensitivity spin label for nuclear magnetic resonance (NMR) was first proposed and then demonstrated to provide orders-of-magnitude signal enhancement in species which are formed from the molecular addition of hydrogen. The phenomenon known as the PASADENA effect (parahydrogen and synthesis allow dramatically enhanced nuclear alignment) derives from the fact that deviation of the parahydrogen mole fraction in a sample of H_2 from its statistical high-temperature limit of 1/4 is associated with an inherent form of spin order. Upon molecular addition of the two protons from a single H_2 molecule into coupled, magnetically inequivalent environments, this order is manifested as large nonequilibrium spin population differences across allowed NMR transitions.", "date": "2001-11-28", "date_type": "published", "publication": "Journal of the American Chemical Society", "volume": "123", "number": "47", "publisher": "American Chemical Society", "pagerange": "11821-11822", "id_number": "CaltechAUTHORS:20170406-074218760", "issn": "0002-7863", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170406-074218760", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1021/ja010572z", "resource_type": "article", "pub_year": "2001", "author_list": "Carson, Paul J.; Bowers, C. Russell; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/anv7q-vrw43", "eprint_id": 3922, "eprint_status": "archive", "datestamp": "2023-08-21 21:19:14", "lastmod": "2023-10-16 16:13:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kempf-J-G", "name": { "family": "Kempf", "given": "James G." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Method for atomic-layer-resolved measurement of polarization fields by nuclear magnetic resonance", "ispublished": "pub", "full_text_status": "public", "keywords": "nuclear magnetic resonance; quadrupole interactions; Stark effect; spin Hamiltonians; two-dimensional electron gas; nuclear polarisation; gallium arsenide; semiconductor quantum wells; semiconductor epitaxial layers; dielectric polarisation", "note": "\u00a92000 American Vacuum Society. \n\n(Received 17 January 2000; accepted 1 May 2000) \n\nThe authors wish to thank Michael Miller for his estimates of the linewidth contribution of homonuclear J-couplings. This work was supported by NSF Grant No. CHE-9612226.", "abstract": "A nuclear magnetic resonance (NMR) method of probing the dielectric response to an alternating electric field is described, which is applicable to noncentrosymmetric sites with nuclear spin I>1/2. A radio-frequency electric field induces a linear quadrupole Stark effect at a multiple of the nuclear Larmor frequency. This perturbation is applied in the windows of an NMR multiple-pulse line-narrowing sequence in such a way that the resulting nonsecular spin interactions are observed as first-order quadrupole satellites, free of line broadening by the usual dominant static interactions. A simulation of the 69Ga spectrum for the nuclei within the two-dimensional electron gas of a 10 nm quantum well predicts resolution of individual atomic layers in single devices due to the spatial dependence of the polarization response of the quantum-confined carriers to the applied field. This method is part of a more general strategy, perturbations observed with enhanced resolution NMR. Experimentally realized examples in GaAs include spectrally resolving electron probability densities surrounding optically relevant point defects and probing the changes in radial electric field associated with the light-on and light-off states of these shallow traps. Adequate sensitivity for such experiments in individual epitaxial structures is achieved by optical nuclear polarization followed by time-domain NMR observed via nuclear Larmor-beat detection of luminescence.", "date": "2000-07", "date_type": "published", "publication": "Journal of Vacuum Science and Technology B", "volume": "18", "number": "4", "publisher": "American Vacuum Society", "pagerange": "2255-2262", "id_number": "CaltechAUTHORS:KEMjvstb00", "issn": "1071-1023", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:KEMjvstb00", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1116/1.1305287", "primary_object": { "basename": "KEMjvstb00.pdf", "url": "https://authors.library.caltech.edu/records/anv7q-vrw43/files/KEMjvstb00.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Kempf, James G. and Weitekamp, Daniel P." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/m40g5-1x308", "eprint_id": 52123, "eprint_status": "archive", "datestamp": "2023-08-19 03:55:36", "lastmod": "2023-10-18 19:35:21", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mueller-L-J", "name": { "family": "Mueller", "given": "Leonard J." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Quantum Statistical Corrections to Dynamic Nuclear Magnetic Resonance", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1999 American Association for the Advancement of Science.\n\nReceived 30 April 1998; accepted 16 November 1998.\n\nThis work was supported by NSF (grant CHE-9005964). L.J.M. acknowledges an NSF Graduate Fellowship\nand a Department of Defense National Defense\nScience and Engineering Graduate Fellowship.", "abstract": "A quantum statistical treatment of the chemical exchange between molecular eigenstates or conformations revealed previously unsuspected dynamic terms in the spin Hamiltonian operator that describes fast exchange. These terms resulted from the effect of nuclear spin on rotational and vibrational relaxation. With the traditional theory, an interpretation of new carbon-13 nuclear magnetic resonance measurements of the chemical shift of methylcyclohexane in solution showed fast-exchange equilibrium constants that were inconsistent with the slow-exchange free-energy difference and were spread over a range of 30 percent for the various carbon-13 positions. Modeling of the new terms indicated that they have the correct magnitude and temperature dependence to reconcile these inconsistencies.", "date": "1999-01-01", "date_type": "published", "publication": "Science", "volume": "283", "number": "5398", "publisher": "American Association for the Advancement of Science", "pagerange": "61-65", "id_number": "CaltechAUTHORS:20141125-082827667", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141125-082827667", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CHE-9005964" }, { "agency": "NSF Graduate Fellowship" }, { "agency": "National Defense Science and Engineering Graduate (NDSEG) Fellowship" } ] }, "doi": "10.1126/science.283.5398.61", "resource_type": "article", "pub_year": "1999", "author_list": "Mueller, Leonard J. and Weitekamp, Daniel P." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tjxnh-5fw76", "eprint_id": 10856, "eprint_status": "archive", "datestamp": "2023-08-22 10:35:02", "lastmod": "2023-10-16 23:08:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marohn-J-A", "name": { "family": "Marohn", "given": "J. A." } }, { "id": "Carson-P-J", "name": { "family": "Carson", "given": "P. J." } }, { "id": "Hwang-J-Y", "name": { "family": "Hwang", "given": "J. Y." } }, { "id": "Miller-M-A", "name": { "family": "Miller", "given": "M. A." }, "orcid": "0000-0002-3964-9312" }, { "id": "Shykind-D-N", "name": { "family": "Shykind", "given": "D. N." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } } ] }, "title": "Optical Larmor Beat Detection of High-Resolution Nuclear Magnetic Resonance in a Semiconductor Heterostructure", "ispublished": "pub", "full_text_status": "public", "note": "\u00a91995 The American Physical Society. \n\nReceived 20 March 1995. \n\nThis work was funded by the NSF program in Materials Synthesis and processing and by NASA through the Caltech President's Fund. We thank A. Ksendzov, J. Liu, and F. Grunthaner of the NASA Jet Propulsion Laboratory's Center for Space Microelectronics Technology for sample preparation and luminescence characterization, and L. Burnett and A. Perry for cryogenics advice.", "abstract": "A new method of optical nuclear magnetic resonance, Larmor beat detection, is described and demonstrated on a III-V semiconductor heterostructure. Modulation of the circular polarization of luminescence at the difference between two nuclear spin precession frequencies is induced by rf pulses. One isotope provides a spin-locked reference field, while NMR transients of a second isotope are observed optically in real time. Order-of-magnitude improvement in resolution and sensitivity over previous techniques is obtained, revealing weak electric field gradients in single epitaxial structures.", "date": "1995-08-14", "date_type": "published", "publication": "Physical Review Letters", "volume": "75", "number": "7", "publisher": "American Physical Society", "pagerange": "1364-1367", "id_number": "CaltechAUTHORS:MARprl95", "issn": "0031-9007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:MARprl95", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevLett.75.1364", "primary_object": { "basename": "MARprl95.pdf", "url": "https://authors.library.caltech.edu/records/tjxnh-5fw76/files/MARprl95.pdf" }, "resource_type": "article", "pub_year": "1995", "author_list": "Marohn, J. A.; Carson, P. J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xq0vd-zzt36", "eprint_id": 4457, "eprint_status": "archive", "datestamp": "2023-08-22 08:53:12", "lastmod": "2023-10-16 17:46:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Buratto-S-K", "name": { "family": "Buratto", "given": "Steven K." } }, { "id": "Shykind-D-N", "name": { "family": "Shykind", "given": "David N." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Can nuclear magnetic resonance resolve epitaxial layers?", "ispublished": "pub", "full_text_status": "public", "keywords": "NUCLEAR MAGNETIC RESONANCE; ELECTRONIC STRUCTURE; GALLIUM ARSENIDES; COMPUTERIZED SIMULATION; SPATIAL RESOLUTION; EPITAXIAL LAYERS; QUANTUM WELL STRUCTURES; LOCALIZED STATES; LINE SHAPE", "note": "\u00a9 2006 American Vacuum Society \n\n(Received 31 January 1992; accepted 13 March 1992) \n\nThis research is sponsored by the Caltech Consortium in Chemistry and Chemical Engineering; founding members: E. I. du Pont de Nemours and Company Inc., Eastman Kodak Company, and Minnesota Mining and Manufacturing. S.K.B. is an AT&T Bell Laboratories Ph.D. Scholar. D.P.W. is a Camille and Henry Dreyfus Teacher-Scholar.", "abstract": "The recently demonstrated technique of time-sequenced optical nuclear magnetic resonance in GaAs has made possible the detection of spectra free of the line shape distortions that accompanied earlier steady-state methods with an improvement in sensitivity as well. This work examines the possibility of even higher spectral resolution by means of selective averaging with radio frequency-optical multiple-pulse techniques with the aim of isolating the site-specific changes in the spin Hamiltonian associated with excitation to localized states of the conduction band, as in quantum wells. Simulations are presented to evaluate the approach proposed. It is concluded that such experiments are capable of the sensitivity and resolution to resolve individual epitaxial layers in high-quality structures and would provide unprecedented detail on the electronic structure and its uniformity by way of the nuclear quadrupole and spin-averaged hyperfine interactions.", "date": "1992-07", "date_type": "published", "publication": "Journal of Vacuum Science and Technology B", "volume": "10", "number": "4", "publisher": "American Vacuum Society", "pagerange": "1740-1743", "id_number": "CaltechAUTHORS:BURjvstb92", "issn": "1071-1023", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:BURjvstb92", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1116/1.586233", "primary_object": { "basename": "BURjvstb92.pdf", "url": "https://authors.library.caltech.edu/records/xq0vd-zzt36/files/BURjvstb92.pdf" }, "resource_type": "article", "pub_year": "1992", "author_list": "Buratto, Steven K.; Shykind, David N.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0xfx6-82q24", "eprint_id": 10854, "eprint_status": "archive", "datestamp": "2023-08-22 08:27:31", "lastmod": "2023-10-16 23:08:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Buratto-S-K", "name": { "family": "Buratto", "given": "Steven K." } }, { "id": "Shykind-D-N", "name": { "family": "Shykind", "given": "David N." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Time-sequenced optical nuclear magnetic resonance of gallium arsenide", "ispublished": "pub", "full_text_status": "public", "note": "\u00a91991 The American Physical Society. \n\nReceived 22 January 1991. \n\nThis work was supported by the Caltech Consortium in Chemistry and Chemical Engineering: Founding Members: E.I. du Pont de Nemours and Company, and Minnesota Mining and Manufacturing Company. We thank numerous members of the groups of Professor N. Lewis, Professor A. Yariv, and Professor A. Zewail for advice and assistance. S.K.B. acknowledges support by AT&T Bell Laboratories and D.P.W. by the Camille and Henry Dreyfus Foundation.", "abstract": "A method of optical detection of nuclear magnetic resonance is demonstrated in which optical nuclear polarization, spin resonance, and optical detection are separated into distinct sequential periods and separately optimized by varying the optical, rf, and static fields. Experiments on the bulk 69Ga resonance of GaAs show that sites imperceptibly perturbed by the optically relevant defect are optically observable with the rf applied in the dark. A signal-to-noise analysis is given that relates the sensitivity to readily measured material properties and indicates applicability to dilute defects.", "date": "1991-10-15", "date_type": "published", "publication": "Physical Review B", "volume": "44", "number": "16", "publisher": "Physical Review B", "pagerange": "9035-9038", "id_number": "CaltechAUTHORS:BURprb91", "issn": "0163-1829", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:BURprb91", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevB.44.9035", "primary_object": { "basename": "BURprb91.pdf", "url": "https://authors.library.caltech.edu/records/0xfx6-82q24/files/BURprb91.pdf" }, "resource_type": "article", "pub_year": "1991", "author_list": "Buratto, Steven K.; Shykind, David N.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/da92f-cp674", "eprint_id": 91787, "eprint_status": "archive", "datestamp": "2023-08-20 00:14:44", "lastmod": "2024-01-14 21:19:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bowers-C-R", "name": { "family": "Bowers", "given": "C. R." } }, { "id": "Buratto-S-K", "name": { "family": "Buratto", "given": "S. K." } }, { "id": "Carson-P-J", "name": { "family": "Carson", "given": "P. J." } }, { "id": "Cho-H-M", "name": { "family": "Cho", "given": "H. M." } }, { "id": "Hwang-J-Y", "name": { "family": "Hwang", "given": "J. Y." } }, { "id": "Mueller-L-J", "name": { "family": "Mueller", "given": "L. J." } }, { "id": "Pizarro-P-J", "name": { "family": "Pizarro", "given": "P. J." } }, { "id": "Shykind-D-N", "name": { "family": "Shykind", "given": "D. N." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } } ] }, "title": "New approaches to ultrasensitive magnetic resonance", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThis work was supported by the Beckman Institute at Caltech, the National Science Foundation (CHE\u20149005964), and the Caltech Consortium in Chemistry and Chemical Engineering: Founding Members: E.I. du Pont de Nemours and Company, Inc. , Eastman Kodak Company, and Minnesota Mining and Manufacturing Company. J.Y.H., P.J.P. and L.J.M are NSF Graduate Fellows. H.M.C is a Bantrell Fellow. S.K.B is an AT&T\u2014Bell Laboratories Ph.D Scholar. D.P.W. is a Camille and Henry Dreyfus Teacher\u2014Scholar.\n\nPublished - 36.pdf
", "abstract": "Spectroscopic methods tend to exhibit an inverse correlation between sensitivity and the ability to discriminate between similar structures. Were they obtainable with adequate sensitivity, magnetic resonance spectra could resolve structural controversies involving the nature of clusters, ions, semiconductor defects and catalytic intermediates. This paper describes several novel approaches to magnetic resonance, which have in common that the spins are coupled to other degrees of freedom in order to obtain nonequilibrium polarization and/or greater detection sensitivity. The methods under development include single-ion electron spin resonance (ESR) detected by ion trapping frequencies, catalyst NMR detected by the branching ratio to different spin symmetry species, and semiconductor nuclear magnetic resonance (NMR) detected via the circular polarization of luminescence.", "date": "1991-07-01", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "36-50", "id_number": "CaltechAUTHORS:20181213-143630057", "isbn": "9780819405258", "book_title": "Optical Methods for Ultrasensitive Detection and Analysis: Techniques and Applications", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181213-143630057", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Beckman Institute" }, { "agency": "NSF", "grant_number": "CHE-9005964" }, { "agency": "Caltech Consortium in Chemistry and Chemical Engineering" }, { "agency": "NSF Graduate Research Fellowship" }, { "agency": "Bantrell Fellowship" }, { "agency": "AT&T Bell Laboratories" }, { "agency": "Camille and Henry Dreyfus Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "8390", "name": "Arthur Amos Noyes Laboratory of Chemical Physics" } ] }, "contributors": { "items": [ { "id": "Fearey-B-L", "name": { "family": "Fearey", "given": "Bryan L." } } ] }, "doi": "10.1117/12.44229", "primary_object": { "basename": "36.pdf", "url": "https://authors.library.caltech.edu/records/da92f-cp674/files/36.pdf" }, "resource_type": "book_section", "pub_year": "1991", "author_list": "Bowers, C. R.; Buratto, S. K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2pb4t-ss888", "eprint_id": 106444, "eprint_status": "archive", "datestamp": "2023-08-19 22:18:35", "lastmod": "2023-10-20 23:29:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kurur-Narayanan-D", "name": { "family": "Kurur", "given": "Narayanan D." } }, { "id": "Jones-Daniel-H", "name": { "family": "Jones", "given": "Daniel H." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Chemical exchange and quantum exchange", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1990.", "abstract": "The mutual chemical exchange rate has been derived with the rovibrational lattice treated quantum-mechanically. Our formulation contrasts sharply with previous descriptions of the role of tunnelling in NMR lineshapes.", "date": "1990", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "182-183", "id_number": "CaltechAUTHORS:20201104-193125384", "isbn": "9783540531364", "book_title": "25th Congress Ampere on Magnetic Resonance and Related Phenomena: Extended Abstracts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201104-193125384", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "contributors": { "items": [ { "id": "Mehring-M", "name": { "family": "Mehring", "given": "Michael" } }, { "id": "von-Sch\u00fctz-J-U", "name": { "family": "von Sch\u00fctz", "given": "Jost Ulrich" } }, { "id": "Wolf-H-C", "name": { "family": "Wolf", "given": "Hans Christoph" } } ] }, "doi": "10.1007/978-3-642-76072-3_94", "resource_type": "book_section", "pub_year": "1990", "author_list": "Kurur, Narayanan D.; Jones, Daniel H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8qrt5-01263", "eprint_id": 107696, "eprint_status": "archive", "datestamp": "2023-08-19 22:19:35", "lastmod": "2023-10-23 16:08:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bowers-C-Russell", "name": { "family": "Bowers", "given": "C. Russell" } }, { "id": "Carson-Paul-J", "name": { "family": "Carson", "given": "P. J." } }, { "id": "Norris-David-J", "name": { "family": "Norris", "given": "D. J." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } } ] }, "title": "Dihydrogen addition studies by the Pasadena effect", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1990.", "abstract": "Several experiments and theoretical development of the PASADENA effect (parahydrogen and synthesis allow dramatically enchanced nuclear alignment) to solution and solid-state NMR are presented.", "date": "1990", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "148-149", "id_number": "CaltechAUTHORS:20210123-170330175", "isbn": "9783540531364", "book_title": "25th Congress Ampere on Magnetic Resonance and Related Phenomena: Extended Abstracts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210123-170330175", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "contributors": { "items": [ { "id": "Mehring-Michael", "name": { "family": "Mehring", "given": "Michael" } }, { "id": "Ulrich-von-Sch\u00fctz-Jost", "name": { "family": "Ulrich von Sch\u00fctz", "given": "Jost" } }, { "id": "Christoph-Wolf-Hans", "name": { "family": "Christoph Wolf", "given": "Hans" } } ] }, "doi": "10.1007/978-3-642-76072-3_77", "resource_type": "book_section", "pub_year": "1990", "author_list": "Bowers, C. Russell; Carson, P. J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0rfae-p6456", "eprint_id": 10855, "eprint_status": "archive", "datestamp": "2023-08-22 05:03:03", "lastmod": "2023-10-16 23:08:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bowers-C-R", "name": { "family": "Bowers", "given": "C. Russell" } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } } ] }, "title": "Transformation of Symmetrization Order to Nuclear-Spin Magnetization by Chemical Reaction and Nuclear Magnetic Resonance", "ispublished": "pub", "full_text_status": "public", "note": "\u00a91986 The American Physical Society. \n\nReceived 2 July 1986. \n\nThe authors thank the Atlantic Richfield Foundation for partial support of this work.", "abstract": "A method of obtaining very large nuclear-spin polarizations is proposed and illustrated by density-operator calculations. The prediction is that chemical reaction and rf irradiation can convert the scalar parahydrogen state into polarization of order unity on the nuclear spins of the products of molecular-hydrogen addition reactions. A means of extending the resultant sensitivity enhancement to other spins is proposed in which the transfer of order occurs through population differences not associated with magnetization.", "date": "1986-11-24", "date_type": "published", "publication": "Physical Review Letters", "volume": "57", "number": "21", "publisher": "American Physical Society", "pagerange": "2645-2648", "id_number": "CaltechAUTHORS:BOWprl86", "issn": "0031-9007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:BOWprl86", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevLett.57.2645", "primary_object": { "basename": "BOWprl86.pdf", "url": "https://authors.library.caltech.edu/records/0rfae-p6456/files/BOWprl86.pdf" }, "resource_type": "article", "pub_year": "1986", "author_list": "Bowers, C. Russell and Weitekamp, Daniel P." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/16135-bkc94", "eprint_id": 10868, "eprint_status": "archive", "datestamp": "2023-08-22 04:33:32", "lastmod": "2023-10-16 23:09:04", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zax-D-B", "name": { "family": "Zax", "given": "D. B." } }, { "id": "Bielecki-A", "name": { "family": "Bielecki", "given": "A." } }, { "id": "Zilm-K-W", "name": { "family": "Zilm", "given": "K. W." } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "A." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } } ] }, "title": "Zero field NMR and NQR", "ispublished": "pub", "full_text_status": "public", "keywords": "NUCLEAR MAGNETIC RESONANCE, NUCLEAR QUADRUPOLE RESONANCE, POLYCRYSTALS, MAGNETIC FIELDS, POWDERS, FOURIER TRANSFORMATION, DISORDERED SYSTEMS", "note": "Copyright \u00a9 1985 American Institute of Physics. \n\nReceived 14 June 1985; accepted 7 August 1985. \n\nD.B. Zax was supported by a National Science Foundation Graduate fellowship, and K.W. Zilm by an IBM postdoctoral fellowship. We gratefully acknowledge M. Mehring for helpful conversations, H. Zimmermann for synthesizing many of the deuterated molecules, and J. Murdoch for writing several of the computer simulation routines. This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Science Division of the U.S. Department of Energy and by the Director's Program Development Funds of the Lawrence Berkeley Laboratory under Contract No. DE-AC03-76SF00098.", "abstract": "Methods are described and demonstrated for detecting the coherent evolution of nuclear spin observables in zero magnetic field with the full sensitivity of high field NMR. The principle motivation is to provide a means of obtaining solid state spectra of the magnetic dipole and electric quadrupole interactions of disordered systems without the line broadening associated with random orientation with respect to the applied magnetic field. Comparison is made to previous frequency domain and high field methods. A general density operator formalism is given for the experiments where the evolution period is initiated by a sudden switching to zero field and is terminated by a sudden restoration of the field. Analytical expressions for the signals are given for a variety of simple dipolar and quadrupolar systems and numerical simulations are reported for up to six coupled spin-1/2 nuclei. Experimental results are reported or reviewed for 1H, 2D, 7Li, 13C, and 27Al nuclei in a variety of polycrystalline materials. The effects of molecular motion and bodily sample rotation are described. Various extensions of the method are discussed, including demagnetized initial conditions and correlation by two-dimensional Fourier transformation of zero field spectra with themselves or with high field spectra.", "date": "1985-11-15", "date_type": "published", "publication": "Journal of Chemical Physics", "volume": "83", "number": "10", "publisher": "Journal of Chemical Physics", "pagerange": "4877-4905", "id_number": "CaltechAUTHORS:ZAXjcp85", "issn": "0021-9606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:ZAXjcp85", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.449748", "primary_object": { "basename": "ZAXjcp85.pdf", "url": "https://authors.library.caltech.edu/records/16135-bkc94/files/ZAXjcp85.pdf" }, "resource_type": "article", "pub_year": "1985", "author_list": "Zax, D. B.; Bielecki, A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/eazdr-fx842", "eprint_id": 10857, "eprint_status": "archive", "datestamp": "2023-08-22 04:31:53", "lastmod": "2023-10-16 23:08:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cho-H-M", "name": { "family": "Cho", "given": "H. M." } }, { "id": "Lee-C-J", "name": { "family": "Lee", "given": "C. J." } }, { "id": "Shykind-D-N", "name": { "family": "Shykind", "given": "D. N." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } } ] }, "title": "Nutation Sequences for Magnetic Resonance Imaging in Solids", "ispublished": "pub", "full_text_status": "public", "note": "\u00a91985 The American Physical Society. \n\nReceived 15 July 1985. \n\nThe authors thank Professor A. Pines for his support and interest in this work. We also thank G.C. Chingas, A.N. Garroway, and N.M. Szeverenyi for stimulating discussions of their work prior to publication. This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Science Division of the U.S. Department of Energy and by the Director's Program Development Funds of the Lawrence Berkeley Laboratory under Contract No. DE-AC03-76SF00098.", "abstract": "Novel radio-frequency NMR pulse sequences are presented and their application to imaging of solids with use of rf field gradients is discussed. The sequences cause a nuclear spin to precess about the static field direction at a rate proportional to the strength of certain of the pulses. This forced precession is independent of the resonance offset and of couplings to other spins. The pulse-sequence design is described by means of coherent averaging theory and is confirmed experimentally and numerically.", "date": "1985-10-28", "date_type": "published", "publication": "Physical Review Letters", "volume": "55", "number": "18", "publisher": "American Physical Society", "pagerange": "1923-1926", "id_number": "CaltechAUTHORS:CHOprl85", "issn": "0031-9007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:CHOprl85", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevLett.55.1923", "primary_object": { "basename": "CHOprl85.pdf", "url": "https://authors.library.caltech.edu/records/eazdr-fx842/files/CHOprl85.pdf" }, "resource_type": "article", "pub_year": "1985", "author_list": "Cho, H. M.; Lee, C. J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mjwt3-b2p96", "eprint_id": 10865, "eprint_status": "archive", "datestamp": "2023-08-22 03:50:29", "lastmod": "2023-10-16 23:08:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bielecki-A", "name": { "family": "Bielecki", "given": "A." } }, { "id": "Murdoch-J-B", "name": { "family": "Murdoch", "given": "J. B." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Zax-D-B", "name": { "family": "Zax", "given": "D. B." } }, { "id": "Zilm-K-W", "name": { "family": "Zilm", "given": "K. W." } }, { "id": "Zimmermann-H", "name": { "family": "Zimmermann", "given": "H." } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "A." } } ] }, "title": "Fourier transform pure nuclear quadrupole resonance by pulsed field cycling", "ispublished": "pub", "full_text_status": "public", "keywords": "FOURIER TRANSFORM SPECTROSCOPY, NUCLEAR QUADRUPOLE RESONANCE, DEUTERONS, ASYMMETRY, SENSITIVITY, POLYCRYSTALS, DEUTERATION, ANISOLE", "note": "Copyright \u00a9 1984 American Institute of Physics. \n\nReceived 26 October 1983; accepted 30 December 1983. \n\nWe thank E.L. Hahn, R. Kind, and J.A.S. Smith for helpful discussions. One of us (DBZ) acknowledges support by a National Science Foundation Graduate Fellowship, and another of us (KWZ) acknowledges an IBM predoctoral fellowship. This work was supported by the Director, Office of Energy Research, Basic Energy Sciences, Materials Sciences Division of the U.S. Department of Energy under Contract Number DE-AC03-76SF00098.", "abstract": "We report the observation of Fourier transform pure NQR by pulsed field cycling. For deuterium, well resolved spectra are obtained with high sensitivity showing the low frequency nu0 lines and allowing assignments of quadrupole couplings and asymmetry parameters to inequivalent deuterons. The technique is ideally applicable to nuclei with low quadrupolar frequencies (e.g., 2D, 7Li, 11B, 27Al, 23Na, 14N) and makes possible high resolution structure determination in polycrystalline or disordered materials.", "date": "1984-03-01", "date_type": "published", "publication": "Journal of Chemical Physics", "volume": "80", "number": "5", "publisher": "Journal of Chemical Physics", "pagerange": "2232-2234", "id_number": "CaltechAUTHORS:BIEjcp84", "issn": "0021-9606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:BIEjcp84", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.446915", "primary_object": { "basename": "BIEjcp84.pdf", "url": "https://authors.library.caltech.edu/records/mjwt3-b2p96/files/BIEjcp84.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Bielecki, A.; Murdoch, J. B.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tgkzf-q3186", "eprint_id": 10866, "eprint_status": "archive", "datestamp": "2023-08-22 03:42:39", "lastmod": "2023-10-16 23:08:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Duppen-K", "name": { "family": "Duppen", "given": "Koos" } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Wiersma-D-A", "name": { "family": "Wiersma", "given": "Douwe A." } } ] }, "title": "Vibrational dephasing in molecular mixed crystals: A picosecond time domain CARS study of pentacene in naphthalene and benzoic acid", "ispublished": "pub", "full_text_status": "public", "keywords": "MOLECULAR CRYSTALS, NAPHTHALENE, BENZOIC ACID, RAMAN SPECTROSCOPY, VIBRATIONAL STATES, DOPED MATERIALS", "note": "Copyright \u00a9 1983 American Institute of Physics. \n\nReceived 1 June 1983; accepted 31 August 1983. \n\nThe investigations were supported by the Netherlands Foundation for Chemical Research (S.O.N.) with financial aid from the Netherlands Organization for the Advancement of Pure Research (Z.W.O.).", "abstract": "Multiresonant time-domain coherent anti-Stokes Raman scattering (CARS) experiments have been employed in a study of the decay of vibrational coherences of pentacene doped into naphthalene and benzoic acid. In all cases, the CARS decay is found to be exponential, which indicates that the electronic and vibronic inhomogeneities in this system are strongly correlated. The temperature dependence of vibrational dephasing shows no effect of coupling to the lowest-frequency librational mode of pentacene that is known to dominate electronic dephasing. This surprising result can be understood on basis of a dephasing model where rapid coherence exchange exists between a cold vibrational transition and a corresponding near-resonant librationally hot one. For the 767 cm^\u22121 vibrational transition, oscillations of the CARS signal as a function of delay are shown to arise from interference at the detector with a nearby naphthalene host signal. An inconsistency with a previously reported spontaneous Raman study is resolved by showing that the signal observed there is actually site-selected fluorescence.", "date": "1983-12-15", "date_type": "published", "publication": "Journal of Chemical Physics", "volume": "79", "number": "12", "publisher": "Journal of Chemical Physics", "pagerange": "5835-5844", "id_number": "CaltechAUTHORS:DUPjcp83", "issn": "0021-9606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:DUPjcp83", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.445753", "primary_object": { "basename": "DUPjcp83.pdf", "url": "https://authors.library.caltech.edu/records/tgkzf-q3186/files/DUPjcp83.pdf" }, "resource_type": "article", "pub_year": "1983", "author_list": "Duppen, Koos; Weitekamp, D. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/p5tra-x4q98", "eprint_id": 10864, "eprint_status": "archive", "datestamp": "2023-08-22 03:41:50", "lastmod": "2023-10-16 23:08:54", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Garbow-J-R", "name": { "family": "Garbow", "given": "J. R." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "A." } } ] }, "title": "Total spin coherence transfer echo spectroscopy", "ispublished": "pub", "full_text_status": "public", "keywords": "spin echo, nmr spectra, energy\u2212level transitions, magnetic fields, sensitivity, measuring methods", "note": "Copyright \u00a9 1983 American Institute of Physics. \n\nReceived 19 July 1983; accepted 9 August 1983. \n\nThe authors gratefully acknowledge the assistance of Jim Murdoch in the computer simulations and of Dione Carmichael in the preparation of this manuscript. This work was supported by the Director, Office of Energy Research, Basic Energy Sciences, Materials Sciences Division of the U.S. Department of Energy under Contract Number DE-AC03-76SF00098.", "abstract": "The sensitivity of multiple quantum NMR transitions to magnetic field inhomogeneity and the relative phases and amplitudes of multiple quantum lines are discussed. The technique of total spin coherence transfer echo spectroscopy (TSCTES) is described and experimentally demonstrated. The TSCTES method allows multiple quantum spectra to be obtained which are free of inhomogeneous magnet broadening, yet remain sensitive to spin\u2013spin couplings and chemical shift differences. The method takes advantage of the properties of the total spin coherence, the unique transition between the extreme eigenstates of a coupled spin system. Experimental results are reported for partially oriented acetaldehyde and are analyzed in terms of irreducible tensor operators. Limitations on the method and extensions to heteronuclear spin systems are also discussed.", "date": "1983-12-01", "date_type": "published", "publication": "Journal of Chemical Physics", "volume": "79", "number": "11", "publisher": "Journal of Chemical Physics", "pagerange": "5301-5310", "id_number": "CaltechAUTHORS:GARjcp83", "issn": "0021-9606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:GARjcp83", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.445692", "primary_object": { "basename": "GARjcp83.pdf", "url": "https://authors.library.caltech.edu/records/p5tra-x4q98/files/GARjcp83.pdf" }, "resource_type": "article", "pub_year": "1983", "author_list": "Garbow, J. R.; Weitekamp, D. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/x9tee-73469", "eprint_id": 10860, "eprint_status": "archive", "datestamp": "2023-08-22 03:31:33", "lastmod": "2023-10-16 23:08:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Duppen-K", "name": { "family": "Duppen", "given": "Koos" } }, { "id": "Wiersma-D-A", "name": { "family": "Wiersma", "given": "Douwe A." } } ] }, "title": "Delayed four-wave-mixing spectroscopy in molecular crystals: A nonperturbative approach", "ispublished": "pub", "full_text_status": "public", "note": "\u00a91983 The American Physical Society. \n\nReceived 13 September 1982. \n\nThe investigations were supported by the Netherlands Foundation for Chemical Research (Stichting Scheikundig Onderzoek in Nederland) with financial aid from the Netherlands Organization for the Advancement of Pure Research (Nederlandse Organisatie voor Zuiver-Wtenschappelijk Onderzoek).", "abstract": "The delayed or time-domain four-wave-mixing experiment is treated in the regime of intense near-resonant pulses. The interaction with the radiation during both pump and probe pulses is considered to all powers of the electric field amplitude. Analytical results are obtained for an effective four-level system. These include the dependence of the coherence amplitudes on the ratio of the pump-field intensities when there is a large vibrational discrepancy between ground and excited electronic states and a general solution for the unitary time development during the probe pulse. For the first time, delayed coherent anti-Stokes Raman scattering is detected from highly dilute (10-ppm) guest molecules. Illustrative examples are presented for the system of pentacene in benzoic acid at low temperature. Vibronic-free induction decay and the effect of field inhomogeneity across the beam profile are found to be essential for understanding the observed intensity and spectral distribution of the signal beam in the region of optimum pulse intensity.", "date": "1983-06-01", "date_type": "published", "publication": "Physical Review A", "volume": "27", "number": "6", "publisher": "Physical Review A", "pagerange": "3089-3111", "id_number": "CaltechAUTHORS:WEIpra83", "issn": "0556-2791", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:WEIpra83", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevA.27.3089", "primary_object": { "basename": "WEIpra83.pdf", "url": "https://authors.library.caltech.edu/records/x9tee-73469/files/WEIpra83.pdf" }, "resource_type": "article", "pub_year": "1983", "author_list": "Weitekamp, D. P.; Duppen, Koos; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/n60bx-bqe55", "eprint_id": 10858, "eprint_status": "archive", "datestamp": "2023-08-22 03:30:45", "lastmod": "2023-10-16 23:08:40", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Bielecki-A", "name": { "family": "Bielecki", "given": "A." } }, { "id": "Zax-D-B", "name": { "family": "Zax", "given": "D." } }, { "id": "Zilm-K-W", "name": { "family": "Zilm", "given": "K." } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "A." } } ] }, "title": "Zero-Field Nuclear Magnetic Resonance", "ispublished": "pub", "full_text_status": "public", "note": "\u00a91983 The American Physical Society. \n\nReceived 11 March 1983. \n\nOne of us (D.Z.) acknowledges support by a National Science Foundation graduate fellowship and another of us (K.Z.) by an IBM postdoctoral fellowship. This work also supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Science Division of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.", "abstract": "In polycrystalline samples, NMR \"powder spectra\" are broad and much structural information is lost as a result of the orientational disorder. In this Letter Fourier-transform NMR in zero magnetic field is described. With no preferred direction in space, all crystallites contribute equivalently and resolved dipolar splittings can be interpreted directly in terms of internuclear distances. This opens the possiblity of molecular structure determination without the need for single crystals or oriented samples.", "date": "1983-05-30", "date_type": "published", "publication": "Physical Review Letters", "volume": "50", "number": "22", "publisher": "American Physical Society", "pagerange": "1807-1810", "id_number": "CaltechAUTHORS:WEIprl83a", "issn": "0031-9007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:WEIprl83a", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevLett.50.1807", "primary_object": { "basename": "WEIprl83a.pdf", "url": "https://authors.library.caltech.edu/records/n60bx-bqe55/files/WEIprl83a.pdf" }, "resource_type": "article", "pub_year": "1983", "author_list": "Weitekamp, D. P.; Bielecki, A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/sqwjh-x8b20", "eprint_id": 10863, "eprint_status": "archive", "datestamp": "2023-08-22 03:11:57", "lastmod": "2023-10-16 23:08:52", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Garbow-J-R", "name": { "family": "Garbow", "given": "J. R." } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "A." } } ] }, "title": "Determination of dipole coupling constants using heteronuclear multiple quantum NMR", "ispublished": "pub", "full_text_status": "public", "note": "Copyright \u00a9 1982 American Institute of Physics. \n\n(Received 5 April 1982; accepted 27 April 1982) \n\nThe authors gratefully acknowledge the assistance of Jim Murdoch and Steven Sinton in the computer simulations and of Dione Carmichael in the preparation of this manuscript. This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Sciences Division of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098. \n\nErratum: Determination of dipole coupling constants using heteronuclear multiple quantum NMR [J. Chem. Phys. 77, 2870 (1982)] D. P. Weitekamp et al. J. Chem. Phys. 80, 1372 (1984).", "abstract": "The problem of extracting dipole couplings from a system of N spins I = 1/2 and one spin S by NMR techniques is analyzed. The resolution attainable using a variety of single quantum methods is reviewed. The theory of heteronuclear multiple quantum (HMQ) NMR is developed, with particular emphasis being placed on the superior resolution available in HMQ spectra. Several novel pulse sequences are introduced, including a two-step method for the excitation of HMQ coherence. Experiments on partially oriented [1\u221213C] benzene demonstrate the excitation of the necessary HMQ coherence and illustrate the calculation of relative line intensities. Spectra of high order HMQ coherence under several different effective Hamiltonians achievable by multiple pulse sequences are discussed. A new effective Hamiltonian, scalar heteronuclear recoupled interactions by multiple pulse (SHRIMP), achieved by the simultaneous irradiation of both spin species with the same multiple pulse sequence, is introduced. Experiments are described which allow heteronuclear couplings to be correlated with an S-spin spreading parameter in spectra free of inhomogeneous broadening.", "date": "1982-09-15", "date_type": "published", "publication": "Journal of Chemical Physics", "volume": "77", "number": "6", "publisher": "Journal of Chemical Physics", "pagerange": "2870-2883", "id_number": "CaltechAUTHORS:WEIjcp82", "issn": "0021-9606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:WEIjcp82", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.444180", "primary_object": { "basename": "WEIjcp82.pdf", "url": "https://authors.library.caltech.edu/records/sqwjh-x8b20/files/WEIjcp82.pdf" }, "related_objects": [ { "basename": "WEIjcp82corr.pdf", "url": "https://authors.library.caltech.edu/records/sqwjh-x8b20/files/WEIjcp82corr.pdf" } ], "resource_type": "article", "pub_year": "1982", "author_list": "Weitekamp, D. P.; Garbow, J. R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5e3h7-y3t46", "eprint_id": 10867, "eprint_status": "archive", "datestamp": "2023-08-22 02:27:42", "lastmod": "2023-10-16 23:09:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Warren-W-S", "name": { "family": "Warren", "given": "W. S." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "A." } } ] }, "title": "Theory of selective excitation of multiple-quantum transitions", "ispublished": "pub", "full_text_status": "public", "keywords": "ENERGY\u2013LEVEL TRANSITIONS, EXCITATION, ABSORPTION SPECTRA, NMR SPECTRA, ZEEMAN EFFECT", "note": "Copyright \u00a9 1980 American Institute of Physics. \n\n(Received 18 April 1980; accepted 12 May 1980) \n\nWe wish to thank Gary Drobny, Dr. Luciano Mueller, James Murdoch, Steve Sinton, and Jau Tang for stimulating discussions, and Terry Judson for her patience in typing the manuscript. W.S.W. holds a National Science Foundation Graduate Fellowship. This research was supported by the Division of Materials Sciences, Office of Basic Energy Sciences, U.S. Department of Energy under contract no. W-7405-Eng-48.", "abstract": "The question of whether a molecule can be made to absorb and emit photons only in groups of n is treated. Pulse sequences are introduced which in effect selectively induce the absorption of only groups of n photons. This causes only n-quantum transitions even when many other transitions might be resonant. The technique involves repeated phase shifts of 2pi/n in the radiation to build up the selected coherences and cancel all other coherences, and is applicable to a wide range of spectroscopic systems. Coherent averaging theory is extended to describe selective sequences and demonstrates that n-quantum selectivity is possible to arbitrarily high order in the average Hamiltonian expansion. High-order selectivity requires many phase shifts, however, and for this reason the residual nonselective effects of sequences which are selective to only a finite order are calculated. Selective sequences are applied to the multiple-quantum NMR of oriented molecules, where in combination with time reversal sequences they produce a much more efficient transfer of the population differences into selected coherences than is obtainable by normal wideband pumping. For example, the 10-quantum transition in a 10-spin system can be enhanced by more than four orders of magnitude. Experiments on selective excitaiton of the 4-quantum transitions in oriented benzene verify the expected enhancement.", "date": "1980-09-01", "date_type": "published", "publication": "Journal of Chemical Physics", "volume": "73", "number": "5", "publisher": "Journal of Chemical Physics", "pagerange": "2084-2099", "id_number": "CaltechAUTHORS:WARjcp80", "issn": "0021-9606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:WARjcp80", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1063/1.440403", "primary_object": { "basename": "WARjcp80.pdf", "url": "https://authors.library.caltech.edu/records/5e3h7-y3t46/files/WARjcp80.pdf" }, "resource_type": "article", "pub_year": "1980", "author_list": "Warren, W. S.; Weitekamp, D. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7dxy5-zb240", "eprint_id": 10859, "eprint_status": "archive", "datestamp": "2023-08-22 02:11:58", "lastmod": "2023-10-16 23:08:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Warren-W-S", "name": { "family": "Warren", "given": "W. S." } }, { "id": "Sinton-S", "name": { "family": "Sinton", "given": "S." } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "D. P." } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "A." } } ] }, "title": "Selective Excitation of Multiple-Quantum Coherence in Nuclear Magnetic Resonance", "ispublished": "pub", "full_text_status": "public", "note": "\u00a91979 The American Physical Society. \n\nReceived 24 September 1979. \n\nWe thank G. Drobny, J. Murdoch, and J. Tang for illuminating discussions. One of us (W.S.W.) acknowledges receipt of a National Science Foundation Graduate Fellowship. This work was supported by the Division of Materials Sciences, Office of Basic Energy Sciences, under Contract No. W-7405-Eng-48.", "abstract": "Wideband selective n-quantum excitation in the NMR of coupled spins is demonstrated for the first time. By a combination of multiple pulse averaging and phase shifts \u03d5 a pure n-quantum excitation operator can be produced (n=2\u03c0 / \u03d5). This allows enhancement of normally weak n-quantum transitions. Selective excitation of the zero- and four-quantum transitions in benzene illustrates this approach. Extensions to selective absorption of only groups of n photons in other regimes of spectroscopy are straight-forward, in principle.", "date": "1979-12-10", "date_type": "published", "publication": "Physical Review Letters", "volume": "43", "number": "24", "publisher": "American Physical Society", "pagerange": "1791-1794", "id_number": "CaltechAUTHORS:WARprl79", "issn": "0031-9007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:WARprl79", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1103/PhysRevLett.43.1791", "primary_object": { "basename": "WARprl79.pdf", "url": "https://authors.library.caltech.edu/records/7dxy5-zb240/files/WARprl79.pdf" }, "resource_type": "article", "pub_year": "1979", "author_list": "Warren, W. S.; Sinton, S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mrp1w-tdg29", "eprint_id": 32781, "eprint_status": "archive", "datestamp": "2023-08-19 11:03:31", "lastmod": "2023-10-18 16:17:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Drobny-G", "name": { "family": "Drobny", "given": "Gary" } }, { "id": "Pines-A", "name": { "family": "Pines", "given": "Alexander" } }, { "id": "Sinton-S", "name": { "family": "Sinton", "given": "Steven" } }, { "id": "Weitekamp-D-P", "name": { "family": "Weitekamp", "given": "Daniel P." } }, { "id": "Wemmer-D", "name": { "family": "Wemmer", "given": "David" } } ] }, "title": "Fourier Transform Multiple Quantum Nuclear Magnetic\n Resonance", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1978 Royal Society of Chemistry. Received 18th December, 1978. We would like to acknowledge the help of Mr. Sidney Wolfe in synthesis of the liquid crystals and of Terry Judson in preparation of the manuscript. Support for this work was by the Division of Materials Sciences, Office of Basic Energy Sciences,\nU.S. Department of Energy. D.P.W. held a Predoctoral National Science Foundation Fellowship.\n\nPublished - DROfscs78.pdf
Discussion - DROfscs78disc.pdf
", "abstract": "The excitation and detection of multiple quantum transitions in systems of coupled spins offers, among other advantages, an increase in resolution over single quantum n.m.r. since the number of lines decreases as the order of the transition increases. This paper reviews the motivation for detecting multiple quantum transitions by a Fourier transform experiment and describes an experimental approach to high resolution multiple quantum spectra in dipolar systems along with results on some protonated liquid crystal systems. A simple operator formalism for the essential features of the time development is presented and some applications in progress are discussed.", "date": "1978", "date_type": "published", "publication": "Faraday Symposia of the Chemical Society", "volume": "13", "publisher": "Royal Society of Chemistry", "pagerange": "49-55", "id_number": "CaltechAUTHORS:20120730-082639528", "issn": "0301-5696", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120730-082639528", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)" }, { "agency": "NSF Predoctoral Fellowship" } ] }, "doi": "10.1039/FS9781300049", "primary_object": { "basename": "DROfscs78.pdf", "url": "https://authors.library.caltech.edu/records/mrp1w-tdg29/files/DROfscs78.pdf" }, "related_objects": [ { "basename": "DROfscs78disc.pdf", "url": "https://authors.library.caltech.edu/records/mrp1w-tdg29/files/DROfscs78disc.pdf" } ], "resource_type": "article", "pub_year": "1978", "author_list": "Drobny, Gary; Pines, Alexander; et el." } ]