[ { "id": "https://authors.library.caltech.edu/records/zkt65-24m51", "eprint_id": 116310, "eprint_status": "archive", "datestamp": "2023-08-20 08:14:55", "lastmod": "2023-10-24 21:04:56", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Esin-Iliya", "name": { "family": "Esin", "given": "Iliya" }, "orcid": "0000-0003-2959-0617" }, { "id": "Esterlis-Ilya", "name": { "family": "Esterlis", "given": "Ilya" }, "orcid": "0000-0003-4775-9105" }, { "id": "Demler-Eugene-A", "name": { "family": "Demler", "given": "Eugene" }, "orcid": "0000-0002-2499-632X" }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } } ] }, "title": "Generating coherent phonon waves in narrow-band materials: a twisted bilayer graphene phaser", "ispublished": "unpub", "full_text_status": "public", "note": "Attribution 4.0 International (CC BY 4.0).\n\nWe thank Kenneth Burch, Jerome Faist, Mohammad Hafezi, Atac Imamoglu, Cyprian Lewandowski, Marios Michael, Leo Radzihovsky, and Christopher Yang for valuable discussions. G. Refael and I. Esin are grateful for support from the Simons Foundation and the Institute of Quantum Information and Matter, as well as support from the NSF DMR grant number 1839271. E. Demler and I. Esterlis acknowledge support from the ARO grant \"Control of Many-Body States Using Strong Coherent Light-Matter Coupling in Terahertz Cavities\". This work is supported by ARO MURI Grant No. W911NF-16-1-0361, and was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611.\n\n
Submitted - 2207.11245.pdf
", "abstract": "Twisted bilayer graphene (TBG) exhibits extremely low Fermi velocities for electrons, with the speed of sound surpassing the Fermi velocity. This regime enables the use of TBG for amplifying vibrational waves of the lattice through stimulated emission, following the same principles of operation of free-electron lasers. Our work proposes a lasing mechanism relying on the slow-electron bands to produce a coherent beam of acoustic phonons. We propose a device based on undulated electrons in TBG, which we dub the phaser. The device generates phonon beams in a terahertz (THz) frequency range, which can then be used to produce THz electromagnetic radiation. The ability to generate coherent phonons in solids breaks new ground in controlling quantum memories, probing quantum states, realizing non-equilibrium phases of matter, and designing new types of THz optical devices.", "date": "2022-08-16", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20220816-183030641", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220816-183030641", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Simons Foundation" }, { "agency": "Institute for Quantum Information and Matter (IQIM)" }, { "agency": "NSF", "grant_number": "DMR-1839271" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-16-1-0361" }, { "agency": "NSF", "grant_number": "PHY-1607611" } ] }, "local_group": { "items": [ { "id": "IQIM" } ] }, "doi": "10.48550/arXiv.2207.11245", "primary_object": { "basename": "2207.11245.pdf", "url": "https://authors.library.caltech.edu/records/zkt65-24m51/files/2207.11245.pdf" }, "resource_type": "monograph", "pub_year": "2022", "author_list": "Esin, Iliya; Esterlis, Ilya; et el." }, { "id": "https://authors.library.caltech.edu/records/06ybb-rx004", "eprint_id": 114894, "eprint_status": "archive", "datestamp": "2023-08-20 07:41:02", "lastmod": "2023-10-24 15:14:54", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Polski-Robert-M", "name": { "family": "Polski", "given": "Robert" }, "orcid": "0000-0003-0887-8099" }, { "id": "Zhang-Yiran", "name": { "family": "Zhang", "given": "Yiran" }, "orcid": "0000-0002-8477-0074" }, { "id": "Peng-Yang", "name": { "family": "Peng", "given": "Yang" }, "orcid": "0000-0002-8868-2928" }, { "id": "Arora-Harpreet-Singh", "name": { "family": "Arora", "given": "Harpreet Singh" }, "orcid": "0000-0002-7674-735X" }, { "id": "Choi-Youngjoon", "name": { "family": "Choi", "given": "Youngjoon" }, "orcid": "0000-0001-9783-5992" }, { "id": "Kim-Hyunjin", "name": { "family": "Kim", "given": "Hyunjin" }, "orcid": "0000-0001-9886-0487" }, { "id": "Watanabe-Kenji", "name": { "family": "Watanabe", "given": "Kenji" }, "orcid": "0000-0003-3701-8119" }, { "id": "Taniguchi-Takashi", "name": { "family": "Taniguchi", "given": "Takashi" }, "orcid": "0000-0002-1467-3105" }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } }, { "id": "von-Oppen-Felix", "name": { "family": "von Oppen", "given": "Felix" }, "orcid": "0000-0002-2537-7256" }, { "id": "Nadj-Perge-S", "name": { "family": "Nadj-Perge", "given": "Stevan" }, "orcid": "0000-0002-2394-9070" } ] }, "title": "Hierarchy of Symmetry Breaking Correlated Phases in Twisted Bilayer Graphene", "ispublished": "unpub", "full_text_status": "public", "note": "Attribution 4.0 International (CC BY 4.0).\n\nWe acknowledge discussions with Cyprian Lewandowski, Jason Alicea, and Alex Thomson. \n\nThis work has been primarily supported by the DOE-QIS program (DE-SC0019166) and NSF-CAREER (DMR-1753306). S.N-P. acknowledges support from the Sloan Foundation. G.R. and S.N.-P. also acknowledge the support of the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation through Grant GBMF1250; Y.P. acknowledges support from the startup fund from California State University, Northridge. F.v.O. is supported by Deutsche Forschungsgemeinschaft within CRC 183 (project C02) as well as the project TWISTGRAPH. \n\nAuthor Contribution: R.P. and Y.Z. performed the measurements, fabricated devices, and analyzed the data. H.P., Y.C., and H.K. helped with device fabrication and data analysis. Y. P. developed a theoretical model and performed model calculations in close collaboration with F.v.O. and G.R. K.W., and T.T. provides hBN crystals. S.N-P. supervised the project. R.P, Y.Z. Y.P., F.v.O. G.R. and S.N-P. wrote the manuscript with the input of other authors. \n\nData availability: The data that support the findings of this study are available from the corresponding authors on reasonable request. \n\nCode availability: The code that support the findings of this study are available from the corresponding authors on reasonable request. \n\nThe authors declare no competing interests.\n\nSubmitted - 2205.05225.pdf
", "abstract": "Twisted bilayer graphene (TBG) near the magic twist angle of \u223c1.1\u00b0 exhibits a rich phase diagram. However, the interplay between different phases and their dependence on twist angle is still elusive. Here, we explore the stability of various TBG phases and demonstrate that superconductivity near filling of two electrons per moir\u00e9 unit cell alongside Fermi surface reconstructions, as well as entropy-driven high-temperature phase transitions and linear-in-T resistance occur over a range of twist angles which extends far beyond those exhibiting correlated insulating phases. In the vicinity of the magic angle, we also find a metallic phase that displays a hysteretic anomalous Hall effect and incipient Chern insulating behaviour. Such a metallic phase can be rationalized in terms of the interplay between interaction-driven deformations of TBG bands leading to Berry curvature redistribution and Fermi surface reconstruction. Our results provide an extensive perspective on the hierarchy of correlated phases in TBG as classified by their robustness against deviations from the magic angle or, equivalently, their electronic interaction requirements.", "date": "2022-05-24", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20220524-180258498", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220524-180258498", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-SC0019166" }, { "agency": "NSF", "grant_number": "DMR-1753306" }, { "agency": "Alfred P. Sloan Foundation" }, { "agency": "Institute for Quantum Information and Matter (IQIM)" }, { "agency": "Gordon and Betty Moore Foundation", "grant_number": "GBMF1250" }, { "agency": "California State University, Northridge" }, { "agency": "Deutsche Forschungsgemeinschaft (DFG)", "grant_number": "CRC 183" } ] }, "local_group": { "items": [ { "id": "IQIM" } ] }, "doi": "10.48550/arXiv.2205.05225", "primary_object": { "basename": "2205.05225.pdf", "url": "https://authors.library.caltech.edu/records/06ybb-rx004/files/2205.05225.pdf" }, "resource_type": "monograph", "pub_year": "2022", "author_list": "Polski, Robert; Zhang, Yiran; et el." }, { "id": "https://authors.library.caltech.edu/records/3y6s2-zzm18", "eprint_id": 114112, "eprint_status": "archive", "datestamp": "2023-08-20 07:11:40", "lastmod": "2024-01-29 16:37:05", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Esin-Iliya", "name": { "family": "Esin", "given": "Iliya" }, "orcid": "0000-0003-2959-0617" }, { "id": "Kuhlenkamp-Clemens", "name": { "family": "Kuhlenkamp", "given": "Clemens" }, "orcid": "0000-0001-5529-4358" }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } }, { "id": "Berg-Erez", "name": { "family": "Berg", "given": "Erez" }, "orcid": "0000-0001-8956-3384" }, { "id": "Rudner-Mark-S", "name": { "family": "Rudner", "given": "Mark S." }, "orcid": "0000-0002-5150-6234" }, { "id": "Lindner-Netanel-H", "name": { "family": "Lindner", "given": "Netanel H." }, "orcid": "0000-0003-1879-3902" } ] }, "title": "Universal transport in periodically driven systems without long-lived quasiparticles", "ispublished": "unpub", "full_text_status": "public", "note": "Attribution 4.0 International (CC BY 4.0) \n\nWe would like to thank Ervand Kandelaki and Michael Knap for illuminating discussions, and David Cohen and Yan Katz for technical support. N. L. acknowledges support from the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (Grant Agreement No. 639172), and from the Israeli Center of Research Excellence (I-CORE) \"Circle of Light\". M. R. gratefully acknowledges the support of the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (Grant Agreement No. 678862) and the Villum Foundation. M. R. and E. B. acknowledge support from CRC 183 of the Deutsche Forschungsgemeinschaft. G.R. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award desc0019166 and the Simons Foundation.\n\nSubmitted - 2203.01313.pdf
", "abstract": "An intriguing regime of universal charge transport at high entropy density has been proposed for periodically driven interacting one-dimensional systems with Bloch bands separated by a large single-particle band gap. For weak interactions, a simple picture based on well-defined Floquet quasiparticles suggests that the system should host a quasisteady state current that depends only on the populations of the system's Floquet-Bloch bands and their associated quasienergy winding numbers. Here we show that such topological transport persists into the strongly interacting regime where the single-particle lifetime becomes shorter than the drive period. Analytically, we show that the value of the current is insensitive to interaction-induced band renormalizations and lifetime broadening when certain conditions are met by the system's non-equilibrium distribution function. We show that these conditions correspond to a quasisteady state. We support these predictions through numerical simulation of a system of strongly interacting fermions in a periodically-modulated chain of Sachdev-Ye-Kitaev dots. Our work establishes universal transport at high entropy density as a robust far from equilibrium topological phenomenon, which can be readily realized with cold atoms in optical lattices.", "date": "2022-03-02", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20220329-173619034", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220329-173619034", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "European Research Council (ERC)", "grant_number": "639172" }, { "agency": "I-CORE Program of the Planning and Budgeting Committee" }, { "agency": "European Research Council (ERC)", "grant_number": "678862" }, { "agency": "Villum Foundation" }, { "agency": "Deutsche Forschungsgemeinschaft (DFG)", "grant_number": "CRC 183" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-SC0019166" }, { "agency": "Simons Foundation" } ] }, "local_group": { "items": [ { "id": "Walter-Burke-Institute-for-Theoretical-Physics" } ] }, "doi": "10.48550/arXiv.2203.01313", "primary_object": { "basename": "2203.01313.pdf", "url": "https://authors.library.caltech.edu/records/3y6s2-zzm18/files/2203.01313.pdf" }, "resource_type": "monograph", "pub_year": "2022", "author_list": "Esin, Iliya; Kuhlenkamp, Clemens; et el." }, { "id": "https://authors.library.caltech.edu/records/0pn1a-12057", "eprint_id": 113596, "eprint_status": "archive", "datestamp": "2023-09-15 07:33:31", "lastmod": "2023-10-23 21:36:11", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Nathan-Frederik", "name": { "family": "Nathan", "given": "Frederik" }, "orcid": "0000-0001-9700-0231" }, { "id": "Martin-Ivar", "name": { "family": "Martin", "given": "Ivar" }, "orcid": "0000-0002-2010-6449" }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } } ] }, "title": "Topological frequency conversion in Weyl semimetals", "ispublished": "unpub", "full_text_status": "public", "note": "We thank Mark Rudner, Prineha Narang, Chris Ciccarino, and N. Peter Armitage for valuable discussions. FN gratefully acknowledges the support of the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (Grant Agreement No. 678862) and the Villum Foundation. IM was supported by the Materials Sciences and Engineering Division, Basic Energy Sciences, Office of Science, U.S. Department of Energy. GR is grateful for support from the Simons Foundation as well as support from the NSF DMR grant number 1839271. This work is supported by ARO MURI Grant No. W911NF-16-1-0361, and was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611.\n\nSubmitted - 2201.07804.pdf
", "abstract": "We show that a Weyl semimetal irradiated at two distinct frequencies can convert energy between the frequencies at a potentially large rate. The phenomenon is a realization of topological frequency conversion from [Martin et al, PRX 7 041008 (2017)]. When the effect is realized, each electron near a Weyl point acts as a topological frequency converter, and converts energy at a universal rate given by Planck's constant multiplied by the product of the two frequencies. Our results indicate that Weyl points in TaAs support topological frequency conversion in the THz regime at achievable intensities of order 100 W/mm2. When the topological energy conversion rate exceeds the dissipation rate, the effect can be used for optical amplification. This amplification regime can be achieved when the relaxation rate of the system is larger than the characteristic driving period. This phenomenon further amplifies Weyl semimetals' promise for optical amplification and terahertz (THz) generation.", "date": "2022-02-28", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20220224-200907852", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220224-200907852", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "European Research Council (ERC)", "grant_number": "678862" }, { "agency": "Villum Foundation" }, { "agency": "Department of Energy (DOE)" }, { "agency": "Simons Foundation" }, { "agency": "NSF", "grant_number": "DMR-1839271" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-16-1-0361" }, { "agency": "NSF", "grant_number": "PHY-1607611" } ] }, "local_group": { "items": [ { "id": "IQIM" } ] }, "doi": "10.48550/arXiv.2201.07804", "primary_object": { "basename": "2201.07804.pdf", "url": "https://authors.library.caltech.edu/records/0pn1a-12057/files/2201.07804.pdf" }, "resource_type": "monograph", "pub_year": "2022", "author_list": "Nathan, Frederik; Martin, Ivar; et el." }, { "id": "https://authors.library.caltech.edu/records/n990w-e2f28", "eprint_id": 112906, "eprint_status": "archive", "datestamp": "2023-08-20 06:20:08", "lastmod": "2023-10-23 22:50:44", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhang-Yiran", "name": { "family": "Zhang", "given": "Yiran" }, "orcid": "0000-0002-8477-0074" }, { "id": "Polski-Robert-M", "name": { "family": "Polski", "given": "Robert" }, "orcid": "0000-0003-0887-8099" }, { "id": "Lewandowski-Cyprian", "name": { "family": "Lewandowski", "given": "Cyprian" }, "orcid": "0000-0002-6944-9805" }, { "id": "Thomson-Alex", "name": { "family": "Thomson", "given": "Alex" }, "orcid": "0000-0002-9938-5048" }, { "id": "Peng-Yang", "name": { "family": "Peng", "given": "Yang" }, "orcid": "0000-0002-8868-2928" }, { "id": "Choi-Youngjoon", "name": { "family": "Choi", "given": "Youngjoon" } }, { "id": "Kim-Hyunjin", "name": { "family": "Kim", "given": "Hyunjin" }, "orcid": "0000-0001-9886-0487" }, { "id": "Watanabe-Kenji", "name": { "family": "Watanabe", "given": "Kenji" }, "orcid": "0000-0003-3701-8119" }, { "id": "Taniguchi-Takashi", "name": { "family": "Taniguchi", "given": "Takashi" }, "orcid": "0000-0002-1467-3105" }, { "id": "Alicea-J", "name": { "family": "Alicea", "given": "Jason" }, "orcid": "0000-0001-9979-3423" }, { "id": "von-Oppen-Felix", "name": { "family": "von Oppen", "given": "Felix" }, "orcid": "0000-0002-2537-7256" }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } }, { "id": "Nadj-Perge-S", "name": { "family": "Nadj-Perge", "given": "Stevan" }, "orcid": "0000-0002-2394-9070" } ] }, "title": "Ascendance of Superconductivity in Magic-Angle Graphene Multilayers", "ispublished": "unpub", "full_text_status": "public", "note": "Attribution 4.0 International (CC BY 4.0).\n\nWe thank Haoxin Zhou and Soudabeh Mashahadi for fruitful discussions. \n\nThis work has been primarily supported by NSF-CAREER award (DMR-1753306), and Office of Naval Research (grant no. N142112635), and Army Research Office under Grant Award W911NF17-1-0323. Nanofabrication efforts have been in part supported by Department of Energy DOE-QIS program (DE-SC0019166). S.N-P. acknowledges support from the Sloan Foundation (grant no. FG-2020-13716). G.R., J.A., and S.N.-P. also acknowledge support of the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation through Grant GBMF1250. C.L. acknowledges support from the Gordon and Betty Moore Foundation's EPiQS Initiative, grant GBMF8682. Y.P. acknowledges support from the startup fund from California State University, Northridge. F.v.O. is supported by CRC 183 (project C02) of Deutsche Forschungsgemeinschaft. \n\nAuthor Contribution: Y.Z. and R.P. performed the measurements, fabricated the devices, and analyzed the data. Y.C. and H.K. helped with device fabrication and data analysis. C.L., A.T. and Y.P. developed theoretical models and performed calculations in close collaboration and guidance by F.v.O., G.R. and J.A. K.W. and T.T. provides hBN crystals. S.N-P. supervised the project. Y.Z., R.P., C.L., A.T., Y.P., F.v.O., G.R., J.A., and S.N-P. wrote the manuscript with the input of other authors. \n\nThe authors declare no competing interests. \n\nData availability: The data supporting the findings of this study are available from the corresponding authors on reasonable request. \n\nCode availability: All code used in modeling in this study is available from the corresponding authors on reasonable request.\n\nSubmitted - 2112.09270.pdf
", "abstract": "Graphene moire superlattices have emerged as a platform hosting and abundance of correlated insulating, topological, and superconducting phases. While the origins of strong correlations and non-trivial topology are shown to be directly linked to flat moire bands, the nature and mechanism of superconductivity remain enigmatic. In particular, only alternating twisted stacking geometries of bilayer and trilayer graphene are found to exhibit robust superconductivity manifesting as zero resistance and Fraunhofer interference patterns. Here we demonstrate that magic-angle twisted tri-, quadri-, and pentalayers placed on monolayer tungsten diselenide exhibit flavour polarization and superconductivity. We also observe insulating states in the trilayer and quadrilayer arising at finite electric displacement fields, despite the presence of dispersive bands introduced by additional graphene layers. Moreover, the three multilayer geometries allow us to identify universal features in the family of graphene moire structures arising from the intricate relations between superconducting states, symmetry-breaking transitions, and van Hove singularities. Remarkably, as the number of layers increases, superconductivity emerges over a dramatically enhanced filling-factor range. In particular, in twisted pentalayers, superconductivity extends well beyond the filling of four electrons per moire unit cell, demonstrating the non-trivial role of the additional bands. Our results highlight the importance of the interplay between flat and dispersive bands in extending superconducting regions in graphene moire superlattices and open new frontiers for developing graphene-based superconductors.", "date": "2022-01-14", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20220113-234609742", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220113-234609742", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "DMR-1753306" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N142112635" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF17-1-0323" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-SC0019166" }, { "agency": "Alfred P. Sloan Foundation", "grant_number": "FG-2020-13716" }, { "agency": "Institute for Quantum Information and Matter (IQIM)" }, { "agency": "Gordon and Betty Moore Foundation", "grant_number": "GBMF1250" }, { "agency": "Gordon and Betty Moore Foundation", "grant_number": "GBMF8682" }, { "agency": "California State University, Northridge" }, { "agency": "Deutsche Forschungsgemeinschaft (DFG)", "grant_number": "CRC 183" } ] }, "local_group": { "items": [ { "id": "IQIM" } ] }, "doi": "10.48550/arXiv.2112.09270", "primary_object": { "basename": "2112.09270.pdf", "url": "https://authors.library.caltech.edu/records/n990w-e2f28/files/2112.09270.pdf" }, "resource_type": "monograph", "pub_year": "2022", "author_list": "Zhang, Yiran; Polski, Robert; et el." }, { "id": "https://authors.library.caltech.edu/records/0vv01-b1807", "eprint_id": 112868, "eprint_status": "archive", "datestamp": "2023-08-20 04:41:42", "lastmod": "2023-10-23 22:49:20", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wampler-Matthew", "name": { "family": "Wampler", "given": "Matthew" } }, { "id": "Khor-Brian-J-J", "name": { "family": "Khor", "given": "Brian J. J." } }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } }, { "id": "Klich-Israel", "name": { "family": "Klich", "given": "Israel" }, "orcid": "0000-0002-8979-0170" } ] }, "title": "Stirring by Staring: Measurement Induced Chirality", "ispublished": "unpub", "full_text_status": "public", "note": "I.K. would like to thank Kun-Woo Kim for discussions. The work of I.K., B.J.J.K. and M.W. was supported in part by the NSF grant DMR-1918207. G.R. acknowledges support from the Institute of Quantum Information and Matter, an NSF Physics Frontiers Center funded by the Gordon and Betty Moore Foundation, and the Simons Foundation, as well as to the NSF DMR grant number 1839271. This work was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611.\n\nSubmitted - 2108.05906.pdf
", "abstract": "Controlling the dynamics of quantum systems is a current frontier of quantum many-body physics. Recent advancements in experimental techniques suggest exciting new directions in drive-induced quantum states. Here, we present a simple scheme that relies solely on occupation measurements to induce a chiral quantum phase. Namely, we show that by utilizing a pattern of repeated quantum measurements we can produce chiral edge transport of fermions hopping on a Lieb lattice. We study in detail the dependence on measurement frequency, showing that in the Zeno limit the system can be described by a classical stochastic dynamics, yielding protected transport. As the frequency of measurements is reduced, the charge flow is reduced and vanishes when no measurements are done.", "date": "2021-08-12", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20220113-182208459", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220113-182208459", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "DMR-1918207" }, { "agency": "Institute for Quantum Information and Matter (IQIM)" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Simons Foundation" }, { "agency": "NSF", "grant_number": "DMR-1839271" }, { "agency": "NSF", "grant_number": "PHY-1607611" } ] }, "local_group": { "items": [ { "id": "IQIM" } ] }, "doi": "10.48550/arXiv.2108.05906", "primary_object": { "basename": "2108.05906.pdf", "url": "https://authors.library.caltech.edu/records/0vv01-b1807/files/2108.05906.pdf" }, "resource_type": "monograph", "pub_year": "2021", "author_list": "Wampler, Matthew; Khor, Brian J. J.; et el." }, { "id": "https://authors.library.caltech.edu/records/zkfxy-f6k81", "eprint_id": 105619, "eprint_status": "archive", "datestamp": "2023-08-19 23:15:48", "lastmod": "2023-10-20 22:11:23", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chaudhary-Swati", "name": { "family": "Chaudhary", "given": "Swati" } }, { "id": "Ron-Alon", "name": { "family": "Ron", "given": "Alon" } }, { "id": "Hsieh-David", "name": { "family": "Hsieh", "given": "David" }, "orcid": "0000-0002-0812-955X" }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } } ] }, "title": "Controlling ligand-mediated exchange interactions in periodically driven magnetic materials", "ispublished": "unpub", "full_text_status": "public", "note": "We acknowledge support from the IQIM, an NSF Physics Frontiers Center funded through grant PHY-1733907. We are grateful for support from ARO MURI W911NF-16-1-0361 \"Quantum Materials by Design with Electromagnetic Excitation\" sponsored by the U.S. Army. GR is also grateful for support from the Simons Foundation and the Packard Foundation. AR is grateful for support from Zuckerman STEM leadership program.\n\nSubmitted - 2009.00813.pdf
", "abstract": "A periodic drive could alter the effective exchange interactions in magnetic materials. Here, we explore how exchange pathways affect the effective interactions of periodically driven magnetic materials. Aiming to apply Floquet engineering methods to two-dimensional magnetic materials, we consider realistic models and discuss the effect of a periodic drive on ligand-mediated exchange interactions. We show that depending on bond angles and the number of ligand ions involved in the exchange process, drive-induced changes can be very different from those calculated from direct-hopping models considered earlier. We study these effects and find that the presence of ligand ions must be taken into account, especially for TMTCs where ligand ion mediated next-neighbor interactions play a crucial role in determining the magnetic ground state of the system.", "date": "2020-09-28", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20200928-150652942", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200928-150652942", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Institute for Quantum Information and Matter (IQIM)" }, { "agency": "NSF", "grant_number": "PHY-1733907" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-16-1-0361" }, { "agency": "Simons Foundation" }, { "agency": "David and Lucile Packard Foundation" }, { "agency": "Zuckerman STEM Leadership Program" } ] }, "local_group": { "items": [ { "id": "IQIM" } ] }, "doi": "10.48550/arXiv.2009.00813", "primary_object": { "basename": "2009.00813.pdf", "url": "https://authors.library.caltech.edu/records/zkfxy-f6k81/files/2009.00813.pdf" }, "resource_type": "monograph", "pub_year": "2020", "author_list": "Chaudhary, Swati; Ron, Alon; et el." }, { "id": "https://authors.library.caltech.edu/records/kx3az-ex716", "eprint_id": 101670, "eprint_status": "archive", "datestamp": "2023-08-19 19:37:54", "lastmod": "2023-10-19 22:56:40", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Haim-Arbel", "name": { "family": "Haim", "given": "Arbel" } }, { "id": "Kueng-R-J", "name": { "family": "Kueng", "given": "Richard" } }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } } ] }, "title": "Variational-Correlations Approach to Quantum Many-body Problems", "ispublished": "unpub", "full_text_status": "public", "note": "We have benefited from discussions with Y. Baum, O. Motrunich, E. P. L. van Nieuwenburg, K. Slagel, and C. D. White. This research was supported by the Institute of Quantum Information and Matter, an NSF Frontier center funded by the Gordon and Betty Moore Foundation, the Packard Foundation, and the Simons foundation. AH acknowledges support from the Walter Burke Institute for Theoretical Physics at Caltech. RK acknowledges funding provided by the Office of Naval Research (Award N00014-17-1-2146) and the Army Research Office (Award W911NF121054).\n\nSubmitted - 2001.06510.pdf
", "abstract": "We investigate an approach for studying the ground state of a quantum many-body Hamiltonian that is based on treating the correlation functions as variational parameters. In this approach, the challenge set by the exponentially-large Hilbert space is circumvented by approximating the positivity of the density matrix, order-by-order, in a way that keeps track of a limited set of correlation functions. In particular, the density-matrix description is replaced by a correlation matrix whose dimension is kept linear in system size, to all orders of the approximation. Unlike the conventional variational principle which provides an upper bound on the ground-state energy, in this approach one obtains a lower bound instead. By treating several one-dimensional spin 1/2 Hamiltonians, we demonstrate the ability of this approach to produce long-range correlations, and a ground-state energy that converges to the exact result. Possible extensions, including to higher-excited states are discussed.", "date": "2020-03-03", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20200303-081122185", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200303-081122185", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Institute of Quantum Information and Matter (IQIM)" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "David and Lucile Packard Foundation" }, { "agency": "Simons Foundation" }, { "agency": "Walter Burke Institute for Theoretical Physics, Caltech" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-17-1-2146" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF121054" } ] }, "local_group": { "items": [ { "id": "IQIM" }, { "id": "Walter-Burke-Institute-for-Theoretical-Physics" } ] }, "doi": "10.48550/arXiv.2001.06510", "primary_object": { "basename": "2001.06510.pdf", "url": "https://authors.library.caltech.edu/records/kx3az-ex716/files/2001.06510.pdf" }, "resource_type": "monograph", "pub_year": "2020", "author_list": "Haim, Arbel; Kueng, Richard; et el." }, { "id": "https://authors.library.caltech.edu/records/ht0vt-5qb26", "eprint_id": 47247, "eprint_status": "archive", "datestamp": "2023-08-19 23:34:37", "lastmod": "2023-10-26 20:26:19", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lindner-N-H", "name": { "family": "Lindner", "given": "Netanel H." }, "orcid": "0000-0003-1879-3902" }, { "id": "Refael-G", "name": { "family": "Refael", "given": "Gil" } }, { "id": "von-Oppen-F", "name": { "family": "von Oppen", "given": "Felix" } } ] }, "title": "Enhancement of surface photocurrents in topological insulators using magnetic superlattices", "ispublished": "unpub", "full_text_status": "public", "note": "Imported from arXiv.\n\nSubmitted - 1403.0010v1.pdf
", "abstract": "The gapless surface states of topological insulators (TI) can potentially be used to detect and harvest low-frequency infrared light. Nonetheless, it was shown that significant surface photocurrents due to light with frequency below\nthe bulk gap are rather hard to produce. Here we demonstrate that a periodic\nmagnetic pattern added to the surface dramatically enhances surface photocurrents in TI's . The ability to produce substantial photocurrents on TI surfaces from mid-range and far-infrared light could be used in photovoltaic applications, as well as for detection of micrometer wavelength radiation.", "date": "2014-07-16", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20140715-162801579", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140715-162801579", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Packard Foundation" }, { "agency": "NSF, Physics Frontier Center, Institute for Quantum Information and Matter (IQIM)", "grant_number": "1125565" }, { "agency": "Defense Advanced Research Projects Agency, Functional Engineered Nano Architectonics (FENA)" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Binational Science Foundation (USA-Israel)" }, { "agency": "Deutsche Forschungsgemeinschaft (DFG)" } ] }, "local_group": { "items": [ { "id": "IQIM" } ] }, "doi": "10.48550/arXiv.1403.0010v1", "primary_object": { "basename": "1403.0010v1.pdf", "url": "https://authors.library.caltech.edu/records/ht0vt-5qb26/files/1403.0010v1.pdf" }, "resource_type": "monograph", "pub_year": "2014", "author_list": "Lindner, Netanel H.; Refael, Gil; et el." }, { "id": "https://authors.library.caltech.edu/records/r34va-8s370", "eprint_id": 27512, "eprint_status": "archive", "datestamp": "2023-08-22 03:56:57", "lastmod": "2023-10-24 17:12:37", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Iyer-S", "name": { "family": "Iyer", "given": "S." } }, { "id": "Pekker-D", "name": { "family": "Pekker", "given": "D." } }, { "id": "Refael-G", "name": { "family": "Refael", "given": "G." } } ] }, "title": "A Mott Glass to Superfluid Transition for Random Bosons in Two Dimensions", "ispublished": "unpub", "full_text_status": "public", "keywords": "Disordered Systems and Neural Networks (cond-mat.dis-nn); Superconductivity (cond-mat.supr-con)", "note": "Dated: October 18, 2011.\nIt is our pleasure to acknowledge useful discussions\nwith Anton Akhmerov, Ravin Bhatt, Fran\u00e7ois Cr\u00e9pin,\nDavid Huse, Joel Moore, Nikolai Prokof'ev, Srinivas\nRaghu, Boris Svistunov, Nandini Trivedi, and Ari\nTurner. We particularly thank Olexei Motrunich for\ncomputer time and Bryan Clark for pointing out how\nto estimate errors on the critical exponents that we obtain\nfrom scaling collapse. SI would like to acknowledge\nRobert Dondero for helpful suggestions for resolving\nproblems with the RG code. SI would also like to express\ngratitude to the organizers of the 2010 Boulder School\nfor Condensed Matter and Materials Physics, the 2011\nCarg\u00e8se School on Disordered Systems, and the 2011\nPrinceton Summer School for Condensed Matter Physics.\nSI and DP both thank the 2010 International Centre for\nTheoretical Sciences school in Mysore. This material is\nbased upon work supported, in part, by the National Science\nFoundation under Grant No. 1066293 and the hospitality\nof the Aspen Center for Physics. DP acknowledges\nfinancial support by the Lee A. DuBridge Fellowship, and\nGR acknowledges support from the Packard Foundation.\n\nPublished - 3E474d01.pdf
", "abstract": "We study the zero temperature superfluid-insulator transition for a two-dimensional model of\ninteracting, lattice bosons in the presence of quenched disorder and particle-hole symmetry. We\nfollow the approach of a recent series of papers by Altman, Kafri, Polkovnikov, and Refael, in which\nthe strong disorder renormalization group is used to study disordered bosons in one dimension.\nAdapting this method to two dimensions, we study several different species of disorder and uncover\nuniversal features of the superfluid-insulator transition. In particular, we locate an unstable finite\ndisorder fixed point that governs the transition between the superfluid and a gapless, glassy insulator.\nWe present numerical evidence that this glassy phase is the incompressible Mott glass and that the\ntransition from this phase to the superfluid is driven by percolation-type process. Finally, we provide\nestimates of the critical exponents governing this transition.", "date": "2011-10-14", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20111031-090402654", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111031-090402654", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "1066293" }, { "agency": "Lee A. DuBridge Fellowship" }, { "agency": "Packard Foundation" } ] }, "doi": "10.48550/arXiv.1110.3338", "primary_object": { "basename": "3E474d01.pdf", "url": "https://authors.library.caltech.edu/records/r34va-8s370/files/3E474d01.pdf" }, "resource_type": "monograph", "pub_year": "2011", "author_list": "Iyer, S.; Pekker, D.; et el." } ]