Optical tweezer arrays of neutral atoms have been demonstrated in recent years to be a useful platform for quantum simulation, computation, and metrology. Realizing the full potential of these applications requires increasing qubit numbers while simultaneously maintaining high-fidelity control, which has proved a major challenge across quantum platforms. To date, quantum science experiments have typically been operated with at most hundreds of qubits.
\r\n\r\nIn this thesis, we review the relevant physics of the optical tweezer array architecture and present the technical advances involved in scaling the platform to 6,100 atomic qubits. In tandem with scalability, we demonstrate robust vacuum design, state-of-the-art coherence times, and high single-qubit gate fidelities. To capitalize on the intrinsic connectivity of the architecture at large scale, we investigate long-distance coherent atom transport and briefly describe progress towards two-qubit gate implementation. Finally, we discuss the prospects for scaling the optical tweezer array platform further by an order of magnitude.
", "doi": "10.7907/y7kk-1e96", "publication_date": "2026", "thesis_type": "phd", "thesis_year": "2026" }, { "id": "thesis:16353", "collection": "thesis", "collection_id": "16353", "cite_using_url": "https://resolver.caltech.edu/CaltechTHESIS:04152024-182938221", "primary_object_url": { "basename": "shaw_thesis_final.pdf", "content": "final", "filesize": 28843883, "license": "other", "mime_type": "application/pdf", "url": "/16353/1/shaw_thesis_final.pdf", "version": "v4.0.0" }, "type": "thesis", "title": "Learning, Verifying, and Erasing Errors on a Chaotic and Highly Entangled Programmable Quantum Simulator", "author": [ { "family_name": "Shaw", "given_name": "Adam Lawrence", "orcid": "0000-0002-8059-5950", "clpid": "Shaw-Adam-Lawrence" } ], "thesis_advisor": [ { "family_name": "Endres", "given_name": "Manuel A.", "orcid": "0000-0002-4461-224X", "clpid": "Endres-M" } ], "thesis_committee": [ { "family_name": "Brandao", "given_name": "Fernando", "orcid": "0000-0003-3866-9378", "clpid": "Brand\u00e3o-F-G-S-L" }, { "family_name": "Preskill", "given_name": "John P.", "orcid": "0000-0002-2421-4762", "clpid": "Preskill-J" }, { "family_name": "Hutzler", "given_name": "Nicholas R.", "orcid": "0000-0002-5203-3635", "clpid": "Hutzler-N-R" }, { "family_name": "Nadj-Perge", "given_name": "Stevan", "orcid": "0000-0002-2394-9070", "clpid": "Nadj-Perge-S" }, { "family_name": "Endres", "given_name": "Manuel A.", "orcid": "0000-0002-4461-224X", "clpid": "Endres-M" } ], "local_group": [ { "literal": "div_pma" } ], "abstract": "Controlled quantum systems have the potential to make major advancements in tasks ranging from computing to metrology. In recent years, quantum devices have experienced tremendous progress, reaching meaningful, intermediate-scale sizes and demonstrating advantage over their classical counterparts. Still, sensing, learning, verifying, and hopefully mitigating errors in these systems is an outstanding and ubiquitous challenge facing all modern quantum platforms.
\r\n\r\nHere we review and expound upon one such platform: arrays of Rydberg atoms trapped in optical tweezers. We demonstrate several key advancements, including the first experimental realization of erasure conversion to prepare two-qubit Bell states with a fidelity in excess of 0.999, and to cool atoms to their motional ground state. We further showcase the tools of universal quantum processing via arbitrary single-qubit gates, fixed two-qubit gates, and mid-circuit measurement, and discuss applications of these techniques for metrology and computing.
\r\n\r\nThen, we turn to the many-body regime, generating highly entangled states with up to 60 atoms through analog quench dynamics. We reveal the emergence of random behavior from unitary quantum evolution, and uncover a universal form of quantum ergodicity linking quantum and statistical mechanics. We exploit these discoveries to verify the global many-body fidelity and then realize practical applications like parameter estimation and noise learning. Finally, we compare against both state-of-the-art quantum and classical processors: we introduce a new proxy for the experimental mixed state entanglement which is comparable amongst all quantum platforms, and that reflects the classical complexity of quantum simulation.
", "doi": "10.7907/t7jr-mf97", "publication_date": "2024", "thesis_type": "phd", "thesis_year": "2024" }, { "id": "thesis:14061", "collection": "thesis", "collection_id": "14061", "cite_using_url": "https://resolver.caltech.edu/CaltechTHESIS:01292021-001639979", "type": "thesis", "title": "Entangling, Controlling, and Detecting Individual Strontium Atoms in Optical Tweezer Arrays", "author": [ { "family_name": "Madjarov", "given_name": "Ivaylo Sashkov", "clpid": "Madjarov-Ivaylo-Sashkov" } ], "thesis_advisor": [ { "family_name": "Endres", "given_name": "Manuel A.", "orcid": "0000-0002-4461-224X", "clpid": "Endres-M" } ], "thesis_committee": [ { "family_name": "Hutzler", "given_name": "Nicholas R.", "orcid": "0000-0002-5203-3635", "clpid": "Hutzler-N-R" }, { "family_name": "Endres", "given_name": "Manuel A.", "orcid": "0000-0002-4461-224X", "clpid": "Endres-M" }, { "family_name": "Painter", "given_name": "Oskar J.", "orcid": "0000-0002-1581-9209", "clpid": "Painter-O" }, { "family_name": "Alicea", "given_name": "Jason F.", "orcid": "0000-0001-9979-3423", "clpid": "Alicea-J" } ], "local_group": [ { "literal": "div_pma" } ], "abstract": "We present a novel experimental platform for quantum and precision science: single strontium atoms trapped in arrays of optical tweezers. We demonstrate development of this platform along three important fronts: single-atom trapping, imaging, and cooling; coherent control of the ultra-narrow clock transition; and inter-atom entanglement via Rydberg interactions.
\r\n\r\nIn the context of single-atom physics, we demonstrate trapping in tweezer arrays of one- and two-dimensions as well as cooling to the motional ground state. We furthermore show high-fidelity single-atom imaging with extremely low loss, allowing us to image the same atoms thousands of times before losing them and in principle allowing for the assembly of defect-free atom arrays of several hundred sites.
\r\n\r\nNotably, we show these results in tweezers that are at a magic wavelength for strontium's clock transition. This feature allows us to perform high-fidelity state rotations on the clock transition. We also demonstrate operation of a single-site resolved atomic-array optical clock -- a new atomic clock platform that combines several benefits of optical lattice and single-ion clocks.
\r\n\r\nFrom the metastable clock state, we drive the atoms to highly-excited Rydberg states to introduce interactions between nearby atoms. Using a Rydberg blockade in an assembled array of atom pairs, we demonstrate generation of two-atom entangled Bell states with a fidelity of >98%, or >99% with correction for state preparation and measurement errors. Furthermore, we demonstrate an auto-ionization state-detection scheme for Rydberg atoms which improves on the infidelity of previous Rydberg state-detection schemes by over an order of magnitude.
\r\n\r\nWe conclude with several outlooks, including preliminary data on light-cone correlation spreading in a system of 17 interacting atoms. We also discuss prospects for implementing quantum gates, operating a spin-squeezed clock, increasing system size, quantifying many-body state fidelity, and reducing sources of infidelity.
", "doi": "10.7907/d1em-dt34", "publication_date": "2021", "thesis_type": "phd", "thesis_year": "2021" }, { "id": "thesis:13812", "collection": "thesis", "collection_id": "13812", "cite_using_url": "https://resolver.caltech.edu/CaltechTHESIS:06092020-162351992", "primary_object_url": { "basename": "Senior_Thesis__Anant_Kale_v_1_5.pdf", "content": "final", "filesize": 15146256, "license": "other", "mime_type": "application/pdf", "url": "/13812/1/Senior_Thesis__Anant_Kale_v_1_5.pdf", "version": "v3.0.0" }, "type": "thesis", "title": "Towards High Fidelity Quantum Computation and Simulation with Rydberg Atoms", "author": [ { "family_name": "Kale", "given_name": "Anant M.", "orcid": "0000-0002-7049-5630", "clpid": "Kae-Anant-M" } ], "thesis_advisor": [ { "family_name": "Endres", "given_name": "Manuel A.", "orcid": "0000-0002-4461-224X", "clpid": "Endres-M" } ], "thesis_committee": [ { "family_name": "Libbrecht", "given_name": "Kenneth George", "orcid": "0000-0002-8744-3298", "clpid": "Libbrecht-K-G" }, { "family_name": "Alicea", "given_name": "Jason F.", "orcid": "0000-0001-9979-3423", "clpid": "Alicea-J" }, { "family_name": "Kimble", "given_name": "H. Jeff", "clpid": "Kimble-H-J" }, { "family_name": "Roukes", "given_name": "Michael Lee", "orcid": "0000-0002-2916-6026", "clpid": "Roukes-M-L" }, { "family_name": "Politzer", "given_name": "Hugh David", "orcid": "0000-0002-4983-6621", "clpid": "Politzer-H-D" }, { "family_name": "Frautschi", "given_name": "Steven C.", "clpid": "Frautschi-S-C" }, { "family_name": "Endres", "given_name": "Manuel A.", "orcid": "0000-0002-4461-224X", "clpid": "Endres-M" } ], "local_group": [ { "literal": "div_pma" } ], "abstract": "Individually trapped neutral atoms are a promising candidate for use in quantum computing and simulation applications. They are highly scalable, have long coherence times and can be entangled via strong dipole-dipole interactions by driving to highly excited Rydberg states. However, the fidelity of single atom operations as well as two-atom entangling operations is limited by intrinsic sources of decoherence such as atomic motion, as well as technical sources of noise such as laser intensity fluctuations and phase/frequency fluctuations. We study the effect of these factors on single atom Rabi oscillations and two-atom Rydberg blockaded Rabi oscillations, using perturbation theory and numerical simulation. We develop a window function approach which helps us qualitatively understand the significance of the different spectral components of the noise as well as quantitatively understand the dependence of the Rabi oscillation fidelity on Rabi frequency. This allows us to predict the maximum experimentally achievable fidelities using independent measurements of experimental parameters such as noise spectra and atomic temperature. Turning to the question of near-term scalability of the experimental system, we prototype and test a method of generating a \u2019ladder\u2019 configuration of optical tweezers utilizing two independent lasers. Our setup allows us to fully tune the geometry of the ladder, namely the separation between the two rows, the angle between them, and their relative position along the axis of the ladder. This pseudo-2D configuration enables us to reach larger system sizes in the near future and allows us to access beyond 1D physics.", "doi": "10.7907/8mee-md98", "publication_date": "2020", "thesis_type": "senior_major", "thesis_year": "2020" } ]