{"topic":"atoms-and-ions","sort":"top","limit":25,"offset":0,"count":25,"papers":[{"id":"arxiv:2304.05420","kind":"article","title":"High-fidelity parallel entangling gates on a neutral-atom quantum computer","authors":["Simon J. Evered","Dolev Bluvstein","Marcin Kalinowski","Sepehr Ebadi","Tom Manovitz","Hengyun Zhou","Sophie H. Li","Alexandra A. Geim","Tout T. Wang","Nishad Maskara","Harry Levine","Giulia Semeghini","Markus Greiner","Vladan Vuletić","Mikhail D. Lukin"],"author_count":15,"year":2023,"published":"2023-10-11","venue":"Nature","cited_by":521,"doi":"10.1038/s41586-023-06481-y","arxiv_id":"2304.05420","nct_id":null,"source_url":"https://doi.org/10.1038/s41586-023-06481-y","archive_url":"https://space-kitty.com/papers/arxiv:2304.05420","updated":"2023-04-11","pmid":"37821591","pmcid":null,"openalex_id":"W4387542025","pdf_url":"https://www.nature.com/articles/s41586-023-06481-y.pdf","abstract":"The ability to perform entangling quantum operations with low error rates in a scalable fashion is a central element of useful quantum information processing. Neutral atom arrays have recently emerged as a promising quantum computing platform, featuring coherent control over hundreds of qubits and any-to-any gate connectivity in a flexible, dynamically reconfigurable architecture. The major outstanding challenge has been to reduce errors in entangling operations mediated through Rydberg interactions. Here we report the realization of two-qubit entangling gates with 99.5% fidelity on up to 60 atoms in parallel, surpassing the surface code threshold for error correction. Our method employs fast single-pulse gates based on optimal control, atomic dark states to reduce scattering, and improvements to Rydberg excitation and atom cooling. We benchmark fidelity using several methods based on repeated gate applications, characterize the physical error sources, and outline future improvements. Finally, we generalize our method to design entangling gates involving a higher number of qubits, which we demonstrate by realizing low-error three-qubit gates. By enabling high-fidelity operation in a scalable, highly connected system, these advances lay the groundwork for large-scale implementation of quantum algorithms, error-corrected circuits, and digital simulations.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1605.05207","kind":"article","title":"Quantum computing with atomic qubits and Rydberg interactions: progress and challenges","authors":["Mark E. Saffman"],"author_count":1,"year":2016,"published":"2016-10-04","venue":"Journal of Physics B Atomic Molecular and Optical Physics","cited_by":698,"doi":"10.1088/0953-4075/49/20/202001","arxiv_id":"1605.05207","nct_id":null,"source_url":"https://doi.org/10.1088/0953-4075/49/20/202001","archive_url":"https://space-kitty.com/papers/arxiv:1605.05207","updated":"2016-07-24","pmid":null,"pmcid":null,"openalex_id":"W2398162417","pdf_url":"https://iopscience.iop.org/article/10.1088/0953-4075/49/20/202001/pdf","abstract":"We present a review of quantum computation with neutral atom qubits. After an overview of architectural options and approaches to preparing large qubit arrays we examine Rydberg mediated gate protocols and fidelity for two- and multi-qubit interactions. Quantum simulation and Rydberg dressing are alternatives to circuit based quantum computing for exploring many body quantum dynamics. We review the properties of the dressing interaction and provide a quantitative figure of merit for the complexity of the coherent dynamics that can be accessed with dressing. We conclude with a summary of the current status and an outlook for future progress.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2305.05493","kind":"article","title":"High-fidelity gates and mid-circuit erasure conversion in an atomic qubit","authors":["Shuo Ma","Genyue Liu","Pai Peng","Bichen Zhang","Sven Jandura","Jahan Claes","A. P. Burgers","Guido Pupillo","Shruti Puri","Jeff D. Thompson"],"author_count":10,"year":2023,"published":"2023-10-11","venue":"Nature","cited_by":228,"doi":"10.1038/s41586-023-06438-1","arxiv_id":"2305.05493","nct_id":null,"source_url":"https://doi.org/10.1038/s41586-023-06438-1","archive_url":"https://space-kitty.com/papers/arxiv:2305.05493","updated":"2023-05-09","pmid":"37821593","pmcid":null,"openalex_id":"W4387517741","pdf_url":"https://arxiv.org/pdf/2305.05493","abstract":"The development of scalable, high-fidelity qubits is a key challenge in quantum information science. Neutral atom qubits have progressed rapidly in recent years, demonstrating programmable processors and quantum simulators with scaling to hundreds of atoms. Exploring new atomic species, such as alkaline earth atoms, or combining multiple species can provide new paths to improving coherence, control and scalability. For example, for eventual application in quantum error correction, it is advantageous to realize qubits with structured error models, such as biased Pauli errors or conversion of errors into detectable erasures. In this work, we demonstrate a new neutral atom qubit, using the nuclear spin of a long-lived metastable state in ${}^{171}$Yb. The long coherence time and fast excitation to the Rydberg state allow one- and two-qubit gates with fidelities of 0.9990(1) and 0.980(1), respectively. Importantly, a significant fraction of all gate errors result in decays out of the qubit subspace, to the ground state. By performing fast, mid-circuit detection of these errors, we convert them into erasure errors; during detection, the induced error probability on qubits remaining in the computational space is less than $10^{-5}$. This work establishes metastable ${}^{171}$Yb as a promising platform for realizing fault-tolerant quantum computing.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2201.03540","kind":"article","title":"Erasure conversion for fault-tolerant quantum computing in alkaline earth Rydberg atom arrays","authors":["Yue Wu","Shimon Kolkowitz","Shruti Puri","Jeff D. Thompson"],"author_count":4,"year":2022,"published":"2022-08-09","venue":"Nature Communications","cited_by":197,"doi":"10.1038/s41467-022-32094-6","arxiv_id":"2201.03540","nct_id":null,"source_url":"https://doi.org/10.1038/s41467-022-32094-6","archive_url":"https://space-kitty.com/papers/arxiv:2201.03540","updated":"2022-01-10","pmid":"35945218","pmcid":null,"openalex_id":"W4225985538","pdf_url":"https://www.nature.com/articles/s41467-022-32094-6.pdf","abstract":"Executing quantum algorithms on error-corrected logical qubits is a critical step for scalable quantum computing, but the requisite numbers of qubits and physical error rates are demanding for current experimental hardware. Recently, the development of error correcting codes tailored to particular physical noise models has helped relax these requirements. In this work, we propose a qubit encoding and gate protocol for ${}^{171}$Yb neutral atom qubits that converts the dominant physical errors into erasures, that is, errors in known locations. The key idea is to encode qubits in a metastable electronic level, such that gate errors predominantly result in transitions to disjoint subspaces whose populations can be continuously monitored via fluorescence. We estimate that 98% of errors can be converted into erasures. We quantify the benefit of this approach via circuit-level simulations of the surface code, finding a threshold increase from 0.937% to 4.15%. We also observe a larger code distance near the threshold, leading to a faster decrease in the logical error rate for the same number of physical qubits, which is important for near-term implementations. Erasure conversion should benefit any error correcting code, and may also be applied to design new gates and encodings in other qubit platforms.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum Computing Algorithms and Architecture"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1209.2087","kind":"article","title":"Cooling a single atom in an optical tweezer to its quantum ground state","authors":["Adam M. Kaufman","Brian J. Lester","Cindy A. Regal"],"author_count":3,"year":2012,"published":"2012-09-10","venue":"Physical Review X 2, 041014 (2012)","cited_by":321,"doi":"10.1103/physrevx.2.041014","arxiv_id":"1209.2087","nct_id":null,"source_url":"https://arxiv.org/abs/1209.2087","archive_url":"https://space-kitty.com/papers/arxiv:1209.2087","updated":"2012-11-29","pmid":null,"pmcid":null,"openalex_id":"W2040125422","pdf_url":"https://arxiv.org/pdf/1209.2087","abstract":"We report cooling of a single neutral atom to its three-dimensional vibrational ground state in an optical tweezer. After employing Raman sideband cooling for tens of milliseconds, we measure via sideband spectroscopy a three-dimensional ground-state occupation of ~90%. We further observe coherent control of the spin and motional state of the trapped atom. Our demonstration shows that an optical tweezer, formed simply by a tightly focused beam of light, creates sufficient confinement for efficient sideband cooling. This source of ground-state neutral atoms will be instrumental in numerous quantum simulation and logic applications that require a versatile platform for storing and manipulating ultracold single neutral atoms. For example, these results will improve current optical tweezer experiments studying atom-photon coupling and Rydberg quantum logic gates, and could provide new opportunities such as rapid production of single dipolar molecules or quantum simulation in tweezer arrays.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":false,"retracted":false,"peer_reviewed":null,"categories":["physics.atom-ph","quant-ph"],"details":null,"provenance":"arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1912.08754","kind":"article","title":"Trapped arrays of alkaline earth Rydberg atoms in optical tweezers","authors":["Jack Wilson","Samuel Saskin","Yijian Meng","Shuo Ma","Rohit Dilip","Alex Burgers","Jeff Thompson"],"author_count":7,"year":2019,"published":"2019-12-18","venue":"Phys. Rev. Lett. 128, 033201 (2022)","cited_by":110,"doi":"10.1103/physrevlett.128.033201","arxiv_id":"1912.08754","nct_id":null,"source_url":"https://arxiv.org/abs/1912.08754","archive_url":"https://space-kitty.com/papers/arxiv:1912.08754","updated":"2019-12-19","pmid":"35119888","pmcid":null,"openalex_id":"W4206241545","pdf_url":"https://arxiv.org/pdf/1912.08754","abstract":"Neutral atom qubits with Rydberg-mediated interactions are a leading platform for developing large-scale coherent quantum systems. In the majority of experiments to date, the Rydberg states are not trapped by the same potential that confines ground state atoms, resulting in atom loss and constraints on the achievable interaction time. In this work, we demonstrate that the Rydberg states of an alkaline earth atom, ytterbium, can be stably trapped by the same red-detuned optical tweezer that also confines the ground state, by leveraging the polarizability of the Yb$^+$ ion core. Using the previously unobserved \\tripletS series, we demonstrate trapped Rydberg atom lifetimes exceeding $100\\,μ$s, and observe no evidence of auto- or photo-ionization from the trap light for these states. We measure a coherence time of $T_2 = 59$ $μ$s between two Rydberg levels, exceeding the 28 $μ$s lifetime of untrapped Rydberg atoms under the same conditions. These results are promising for extending the interaction time of Rydberg atom arrays for quantum simulation and computing, and are vital to capitalize on the extended Rydberg lifetimes in circular states or cryogenic environments.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["quant-ph","physics.atom-ph"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1507.05586","kind":"article","title":"Entangling two transportable neutral atoms via local spin exchange","authors":["Adam M. Kaufman","Brian Lester","Michael Foss‐Feig","Michael L. Wall","Ana María Rey","Cindy A. Regal"],"author_count":6,"year":2015,"published":"2015-11-01","venue":"Nature","cited_by":142,"doi":"10.1038/nature16073","arxiv_id":"1507.05586","nct_id":null,"source_url":"https://doi.org/10.1038/nature16073","archive_url":"https://space-kitty.com/papers/arxiv:1507.05586","updated":"2015-11-12","pmid":"26524533","pmcid":null,"openalex_id":"W2117149888","pdf_url":"https://arxiv.org/pdf/1507.05586","abstract":"To advance quantum information science a constant pursuit is the search for physical systems that meet the stringent requirements for creating and preserving quantum entanglement. In atomic physics, robust two-qubit entanglement is typically achieved by strong, long-range interactions in the form of Coulomb interactions between ions or dipolar interactions between Rydberg atoms. While these interactions allow fast gates, atoms subject to these interactions must overcome the associated coupling to the environment and cross-talk among qubits. Local interactions, such as those requiring significant wavefunction overlap, can alleviate these detrimental effects yet present a new challenge: To distribute entanglement, qubits must be transported, merged for interaction, and then isolated for storage and subsequent operations. Here we show how, via a mobile optical tweezer, it is possible to prepare and locally entangle two ultracold neutral atoms, and then separate them while preserving their entanglement. While ground-state neutral atom experiments have measured dynamics consistent with spin entanglement, and detected entanglement with macroscopic observables, we are now able to demonstrate position-resolved two-particle coherence via application of a local gradient and parity measurements; this new entanglement-verification protocol could be applied to arbitrary spin-entangled states of spatially-separated atoms. The local entangling operation is achieved via ultracold spin-exchange interactions, and quantum tunneling is used to combine and separate atoms. Our toolset provides a framework for dynamically entangling remote qubits via local operations within a large-scale quantum register.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1810.10517","kind":"article","title":"Narrow-line cooling and imaging of Ytterbium atoms in an optical tweezer array","authors":["Samuel Saskin","Jack Wilson","Brandon Grinkemeyer","Jeff Thompson"],"author_count":4,"year":2018,"published":"2018-10-24","venue":"Phys. Rev. Lett. 122, 143002 (2019)","cited_by":168,"doi":"10.1103/physrevlett.122.143002","arxiv_id":"1810.10517","nct_id":null,"source_url":"https://arxiv.org/abs/1810.10517","archive_url":"https://space-kitty.com/papers/arxiv:1810.10517","updated":"2018-10-24","pmid":null,"pmcid":null,"openalex_id":"W2897056045","pdf_url":"https://arxiv.org/pdf/1810.10517","abstract":"Engineering controllable, strongly interacting many-body quantum systems is at the frontier of quantum simulation and quantum information processing. Arrays of laser-cooled neutral atoms in optical tweezers have emerged as a promising platform, because of their flexibility and the potential for strong interactions via Rydberg states. Existing neutral atom array experiments utilize alkali atoms, but alkaline-earth atoms offer many advantages in terms of coherence and control, and also open the door to new applications in precision measurement and timekeeping. In this work, we present a technique to trap individual alkaline-earth-like Ytterbium (Yb) atoms in optical tweezer arrays. The narrow $^1S_0$-$^3P_1$ intercombination line is used for both cooling and imaging in a magic-wavelength optical tweezer at 532 nm. The low Doppler temperature allows for imaging near the saturation intensity, resulting in a very high atom detection fidelity. We demonstrate the imaging fidelity concretely by observing rare ($<$ 1 in $10^4$ images) spontaneous quantum jumps into and out of a metastable state. We also demonstrate stochastic loading of atoms into a two-dimensional, 144-site tweezer array. This platform will enable advances in quantum information processing, quantum simulation and precision measurement. The demonstrated narrow-line Doppler imaging may also be applied in tweezer arrays or quantum gas microscopes using other atoms with similar transitions, such as Erbium and Dysprosium.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":false,"retracted":false,"peer_reviewed":null,"categories":["quant-ph","physics.atom-ph"],"details":null,"provenance":"arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2103.12744","kind":"article","title":"Quantum Computing with Circular Rydberg Atoms","authors":["Sam R. Cohen","Jeff D. Thompson"],"author_count":2,"year":2021,"published":"2021-08-06","venue":"PRX Quantum","cited_by":94,"doi":"10.1103/prxquantum.2.030322","arxiv_id":"2103.12744","nct_id":null,"source_url":"https://doi.org/10.1103/prxquantum.2.030322","archive_url":"https://space-kitty.com/papers/arxiv:2103.12744","updated":"2021-03-23","pmid":null,"pmcid":null,"openalex_id":"W3136025248","pdf_url":"http://link.aps.org/pdf/10.1103/PRXQuantum.2.030322","abstract":"Rydberg atom arrays are a leading platform for quantum computing and simulation, combining strong interactions with highly coherent operations and flexible geometries. However, the achievable fidelities are limited by the finite lifetime of the Rydberg states, as well as technical imperfections such as atomic motion. In this work, we propose a novel approach to Rydberg atom arrays using long-lived circular Rydberg states in optical traps. Based on the extremely long lifetime of these states, exceeding seconds in cryogenic microwave cavities that suppress radiative transitions, and gate protocols that are robust to finite atomic temperature, we project that arrays of hundreds of circular Rydberg atoms with two-qubit gate errors around $10^{-5}$ can be realized using current technology. This approach combines several key elements, including a quantum nondemolition detection technique for circular Rydberg states, local manipulation using the ponderomotive potential of focused optical beams, a gate protocol using multiple circular levels to encode qubits, and robust dynamical decoupling sequences to suppress unwanted interactions and errors from atomic motion. This represents a significant improvement on the current state-of-the-art in quantum computing and simulation with neutral atoms.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2406.01482","kind":"article","title":"Spectroscopy and modeling of $^{171}$Yb Rydberg states for high-fidelity two-qubit gates","authors":["Michael Peper","Yiyi Li","Daniel Y. Knapp","Mila Bileska","Shuo Ma","Genyue Liu","Pai Peng","Bichen Zhang","Sebastian P. Horvath","Alex P. Burgers","Jeff D. Thompson"],"author_count":11,"year":2024,"published":"2024-06-03","venue":"Physical Review X","cited_by":56,"doi":"10.1103/physrevx.15.011009","arxiv_id":"2406.01482","nct_id":null,"source_url":"https://arxiv.org/abs/2406.01482","archive_url":"https://space-kitty.com/papers/arxiv:2406.01482","updated":"2024-11-13","pmid":null,"pmcid":null,"openalex_id":"W4406497318","pdf_url":"https://arxiv.org/pdf/2406.01482","abstract":"Highly excited Rydberg states and their interactions play an important role in quantum computing and simulation. These properties can be predicted accurately for alkali atoms with simple Rydberg level structures. However, an extension of these methods to more complex atoms such as alkaline-earth atoms has not been demonstrated or experimentally validated. Here, we present multichannel quantum defect (MQDT) models for highly excited $^{174}$Yb and $^{171}$Yb Rydberg states with $L \\leq 2$. The models are developed using a combination of existing literature data and new, high-precision laser and microwave spectroscopy in an atomic beam, and validated by detailed comparison with experimentally measured Stark shifts and magnetic moments. We then use these models to compute interaction potentials between two Yb atoms, and find excellent agreement with direct measurements in an optical tweezer array. From the computed interaction potential, we identify an anomalous Förster resonance that likely degraded the fidelity of previous entangling gates in $^{171}$Yb using $F=3/2$ Rydberg states. We then identify a more suitable $F=1/2$ state, and achieve a state-of-the-art controlled-Z gate fidelity of $F=0.994(1)$, with the remaining error fully explained by known sources. This work establishes a solid foundation for the continued development of quantum computing, simulation and entanglement-enhanced metrology with Yb neutral atom arrays.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["physics.atom-ph","quant-ph"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1905.05721","kind":"article","title":"Generation and manipulation of Schrödinger cat states in Rydberg atom arrays","authors":["Ahmed Omran","Harry Levine","Alexander Keesling","Giulia Semeghini","Tout T. Wang","Sepehr Ebadi","Hannes Bernien","Alexander S. Zibrov","Hannes Pichler","Soonwon Choi","Jian Cui","Marco Rossignolo","Phila Rembold","Simone Montangero","Tommaso Calarco","Manuel Endres","Markus Greiner","Vladan Vuletić","Mikhail D. Lukin"],"author_count":19,"year":2019,"published":"2019-05-14","venue":"Science 365, 570-574 (2019)","cited_by":634,"doi":"10.1126/science.aax9743","arxiv_id":"1905.05721","nct_id":null,"source_url":"https://arxiv.org/abs/1905.05721","archive_url":"https://space-kitty.com/papers/arxiv:1905.05721","updated":"2019-08-09","pmid":null,"pmcid":null,"openalex_id":"W2967948480","pdf_url":"https://arxiv.org/pdf/1905.05721","abstract":"Quantum entanglement involving coherent superpositions of macroscopically distinct states is among the most striking features of quantum theory, but its realization is challenging, since such states are extremely fragile. Using a programmable quantum simulator based on neutral atom arrays with interactions mediated by Rydberg states, we demonstrate the deterministic generation of 'Schrödinger cat' states of the Greenberger-Horne-Zeilinger (GHZ) type with up to 20 qubits. Our approach is based on engineering the energy spectrum and using optimal control of the many-body system. We further demonstrate entanglement manipulation by using GHZ states to distribute entanglement to distant sites in the array, establishing important ingredients for quantum information processing and quantum metrology.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":false,"retracted":false,"peer_reviewed":null,"categories":["quant-ph","cond-mat.quant-gas","physics.atom-ph"],"details":null,"provenance":"arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"doi:10.1088/2058-9565/aa9c59","kind":"article","title":"Quantum simulation of transverse Ising models with Rydberg atoms","authors":["Peter Schauß"],"author_count":1,"year":2017,"published":"2017-11-22","venue":"Quantum Science and Technology","cited_by":95,"doi":"10.1088/2058-9565/aa9c59","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1088/2058-9565/aa9c59","archive_url":"https://space-kitty.com/papers/doi:10.1088/2058-9565/aa9c59","updated":null,"pmid":null,"pmcid":null,"openalex_id":"W3101767797","pdf_url":"https://iopscience.iop.org/article/10.1088/2058-9565/aa9c59/pdf","abstract":null,"abstract_license":null,"license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex","attribution":"Metadata and citation counts: OpenAlex (CC0)."},{"id":"arxiv:2401.10679","kind":"article","title":"Coherent Control of the Fine-Structure Qubit in a Single Alkaline-Earth Atom","authors":["Govind Unnikrishnan","P. Ilzhöfer","A. Scholz","Christian Hölzl","Aaron Götzelmann","Ratnesh Kumar Gupta","J. Zhao","Johann Krauter","Sebastian Weber","Nastasia Makki","Hans Peter Büchler","Tilman Pfau","Florian Meinert"],"author_count":13,"year":2024,"published":"2024-04-11","venue":"Physical Review Letters","cited_by":48,"doi":"10.1103/physrevlett.132.150606","arxiv_id":"2401.10679","nct_id":null,"source_url":"https://doi.org/10.1103/physrevlett.132.150606","archive_url":"https://space-kitty.com/papers/arxiv:2401.10679","updated":"2024-03-13","pmid":"38682979","pmcid":null,"openalex_id":"W4394715224","pdf_url":"https://arxiv.org/pdf/2401.10679","abstract":"We report on the first realization of a novel neutral atom qubit encoded in the metastable fine-structure states ${^3\\rm{P}_0}$ and ${^3\\rm{P}_2}$ of single $^{88}$Sr atoms trapped in an optical tweezer. Raman coupling of the qubit states promises rapid single-qubit rotations on par with the fast Rydberg-mediated two-body gates. We demonstrate preparation, read-out, and coherent control of the qubit. In addition to driving Rabi oscillations bridging an energy gap of more than 17 THz using a pair of phase-locked clock lasers, we also carry out Ramsey spectroscopy to extract the transverse qubit coherence time $T_2$. When the tweezer is tuned into magic trapping conditions, which is achieved in our setup by tuning the tensor polarizability of the ${^3\\rm{P}_2}$ state via an external control magnetic field, we measure $T_2 = 1.2$ ms. A microscopic quantum mechanical model is used to simulate our experiments including dominant noise sources. We identify the main constraints limiting the observed coherence time and project improvements to our system in the immediate future. Our work opens the door for a so far unexplored qubit encoding concept for neutral atom based quantum computing.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2210.06879","kind":"article","title":"Optimizing Rydberg Gates for Logical-Qubit Performance","authors":["Sven Jandura","Jeff D. Thompson","Guido Pupillo"],"author_count":3,"year":2023,"published":"2023-06-05","venue":"PRX Quantum","cited_by":53,"doi":"10.1103/prxquantum.4.020336","arxiv_id":"2210.06879","nct_id":null,"source_url":"https://doi.org/10.1103/prxquantum.4.020336","archive_url":"https://space-kitty.com/papers/arxiv:2210.06879","updated":"2023-03-31","pmid":null,"pmcid":null,"openalex_id":"W4379470039","pdf_url":"http://link.aps.org/pdf/10.1103/PRXQuantum.4.020336","abstract":"Robust gate sequences are widely used to reduce the sensitivity of gate operations to experimental imperfections. Typically, the optimization minimizes the average gate error, however, recent work in quantum error correction has demonstrated that the performance of encoded logical qubits is sensitive to not only the average error rate, but also the type of errors that occur. Here, we present a family of Rydberg blockade gates for neutral atom qubits that are robust against two common, major imperfections: intensity inhomogeneity and Doppler shifts. These gates outperform existing gates for moderate or large imperfections. We also consider the logical performance of these gates in the context of an erasure-biased qubit based on metastable $~^{171}$Yb. In this case, we observe that the robust gates outperform existing gates for even very small values of the imperfections, because they maintain the native large bias towards erasure errors for these qubits. These results significantly reduce the laser stability and atomic temperature requirements to achieve fault-tolerant quantum computing with neutral atoms. The approach of optimizing gates for logical qubit performance may be applied to other qubit platforms.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2404.13010","kind":"article","title":"High-rate quantum LDPC codes for long-range-connected neutral atom registers","authors":["Laura Pecorari","Sven Jandura","Gavin Keith Brennen","Guido Pupillo"],"author_count":4,"year":2025,"published":"2025-01-28","venue":"Nature Communications","cited_by":30,"doi":"10.1038/s41467-025-56255-5","arxiv_id":"2404.13010","nct_id":null,"source_url":"https://doi.org/10.1038/s41467-025-56255-5","archive_url":"https://space-kitty.com/papers/arxiv:2404.13010","updated":"2025-01-30","pmid":"39875382","pmcid":null,"openalex_id":"W4406891370","pdf_url":"https://www.nature.com/articles/s41467-025-56255-5.pdf","abstract":"High-rate quantum error correcting (QEC) codes with moderate overheads in qubit number and control complexity are highly desirable for achieving fault-tolerant quantum computing. Recently, quantum error correction has experienced significant progress both in code development and experimental realizations, with neutral atom qubit architecture rapidly establishing itself as a leading platform in the field. Scalable quantum computing will require processing with QEC codes that have low qubit overhead and large error suppression, and while such codes do exist, they involve a degree of non-locality that has yet to be integrated into experimental platforms. In this work, we analyze a family of high-rate Low-Density Parity-Check (LDPC) codes with limited long-range interactions and outline a near-term implementation in neutral atom registers. By means of circuit-level simulations, we find that these codes outperform surface codes in all respects when the two-qubit nearest neighbour gate error probability is below $\\sim 0.1\\%$. By using multiple laser colors, we show how these codes can be natively integrated in two-dimensional static neutral atom qubit architectures with open boundaries, where the desired long-range connectivity can be targeted via the Rydberg blockade interaction.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by-nc-nd","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum Computing Algorithms and Architecture"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2109.11551","kind":"article","title":"Any-to-any connected cavity-mediated architecture for quantum computing with trapped ions or Rydberg arrays","authors":["Joshua Ramette","Josiah Sinclair","Zachary Vendeiro","Alyssa Rudelis","Marko Cetina","Vladan Vuletić"],"author_count":6,"year":2021,"published":"2021-09-23","venue":"PRX Quantum","cited_by":63,"doi":"10.1103/prxquantum.3.010344","arxiv_id":"2109.11551","nct_id":null,"source_url":"https://arxiv.org/abs/2109.11551","archive_url":"https://space-kitty.com/papers/arxiv:2109.11551","updated":"2021-09-23","pmid":null,"pmcid":null,"openalex_id":"W3203141358","pdf_url":"https://arxiv.org/pdf/2109.11551","abstract":"We propose a hardware architecture and protocol for connecting many local quantum processors contained within an optical cavity. The scheme is compatible with trapped ions or Rydberg arrays, and realizes teleported gates between any two qubits by distributing entanglement via single-photon transfers through a cavity. Heralding enables high-fidelity entanglement even for a cavity of moderate quality. For processors composed of trapped ions in a linear chain, a single cavity with realistic parameters successfully transfers photons every few $μ$s, enabling the any-to-any entanglement of 20 ion chains containing a total of 500 qubits in 200 $μ$s, with both fidelities and rates limited only by local operations and ion readout. For processors composed of Rydberg atoms, our method fully connects a large array of thousands of neutral atoms. The connectivity afforded by our architecture is extendable to tens of thousands of qubits using multiple overlapping cavities, expanding capabilities for NISQ era algorithms and Hamiltonian simulations, as well as enabling more robust high-dimensional error correcting schemes.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["quant-ph","physics.atom-ph"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"doi:10.1093/nsr/nwy088","kind":"article","title":"Quantum computing with neutral atoms","authors":["Mark E. Saffman"],"author_count":1,"year":2018,"published":"2018-09-09","venue":"National Science Review","cited_by":69,"doi":"10.1093/nsr/nwy088","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1093/nsr/nwy088","archive_url":"https://space-kitty.com/papers/doi:10.1093/nsr/nwy088","updated":null,"pmid":"34691827","pmcid":null,"openalex_id":"W2891267877","pdf_url":"https://academic.oup.com/nsr/article-pdf/6/1/24/27981406/nwy088.pdf","abstract":"The power of quantum computation derives from algorithmic methods that exploit the availability of quantum superposition and entanglement to perform computations that are intractable with classical devices. The race is on to develop hardware that will unleash the promise of quantum algorithms. A handful of different types of hardware are currently being developed with the greatest efforts directed at superconducting, quantum-dot, trapped-ion, photonic, and neutral-atom approaches [1]. While all approaches have strengths and weaknesses, and are at different stages of development, the challenge of creating a practical design that can be scaled to a million or more qubits has not yet been met with any of the existing platforms. One may wonder if we really need a million qubits for a useful quantum computer. The answer depends on our ambition level. On the one hand it is widely believed that a quantum computer with less than 100 reliable qubits will be able to demonstrate a quantum advantage for a well defined computational problem [2]. Demonstration of a quantum computational advantage will generate great excitement in the halls of academia, but will have little broader import. A problem of great practical interest such as ab initio design of chemicals for increasing the yield of fertilizers for crop production, to name but one example, may also require just a few hundred qubits, provided computational sequences with circuit depth of 1010 or more operations can be reliably performed [3]. However, given the current performance of qubit hardware, which has demonstrated error rates not less than ∼10−3, computations with depth 1010 will only produce random outcomes of negligible value. The solution lies in the construction of error-correction circuitry operating on logical qubits, each composed of many physical qubits, which will enable logical error rates many orders of magnitude smaller than physical error rates. Although error correction is remarkably efficient for classical computing devices—Hamming codes detect and correct errors while only requiring roughly 10% overhead in the number of physical bits—quantum error correction is notoriously expensive. New approaches to error correction are the subject of intensive research with one promising direction being the development of codes that are optimized to suppress the dominant error mechanism in a particular physical platform [4,5]. Nevertheless, with physical error rates of 10−4, a plausible target for current qubit systems, the overhead required to reach logical error rates of 10−10 may be measured in thousands of physical qubits for each logical qubit. Thus a quantum computer able to perform deep calculations on a few hundred logical qubits could require a million physical qubits. A consequence of the cost of quantum error correction is that any viable approach to large-scale quantum computing needs to combine high-fidelity quantum logic operations with a capability for integrating large numbers of physical qubits. From this perspective neutral-atom qubits appear particularly promising [6] as they have already demonstrated control of more qubits than any other platform with recent experiments in 1D [7], 2D [8,9], and 3D [10] geometries showing control of up to 50 atomic qubits. Large qubit arrays can potentially be prepared in 1D, 2D, or 3D geometries. The number of proximal qubits increases with the dimensionality, which is advantageous for implementation of error correction code words, and points towards a preference for 2D or 3D arrays. On the other hand, the added overhead of compensating crosstalk incurred when targeting atoms inside a 3D volume makes parallel operations on multiple qubits challenging. A 2D geometry, as shown schematically in Fig. 1, may be an optimal choice since qubit control and measurement can be performed with lasers propagating normal to the plane of the array so that individual qubit sites can be addressed independently. With demonstrated array periods of a few micrometers we require a footprint of less than 1 mm2 for 104 qubits. Conceptual picture of a 2D neutral-atom qubit array. a) High-numerical-aperture lenses project several different wavelengths of light for control and measurement of the qubits. Specific choices of optical wavelengths depend on the atomic species. Not shown are optics for initial laser cooling, transport to the array, beam scanning, and imaging for qubit measurement. b) Averaged fluorescence image of 49 atomic qubits on a 2D grid with |$3.8 \\, {\\mu} \\rm {m}$| spacing [8]. From a fundamental perspective the prospects for scaling neutral-atom systems are particularly promising due to the exceptionally large ratio between coherent and incoherent coupling rates. Neutral-atom qubits are encoded in hyperfine ground states for which coherence times of the order of 10 s have been demonstrated [10]. This implies a dephasing rate |$\\gamma \\sim 0.1 \\, \\rm s^{-1}$|. The coherent coupling that enables quantum logic operations is switched on by exciting atoms to high-lying Rydberg states with principal quantum number close to 100 [11,12]. Rydberg excited atoms at spacings of a few micrometers in an optical lattice interact coherently with rates |$g > 10^9\\, \\rm s^{-1}$|. The ratio between desired coherent coupling and residual incoherent dephasing of g/γ ∼ 1010 establishes a figure of merit that is enabling for scalability. To our knowledge only trapped ions can claim a similar g/γ ratio [13], but without a correspondingly direct path towards controlling thousands of qubits in a single processing unit. Although the g/γ ratio is exceptionally favorable for neutral-atom qubits a complete set of universal gate operations has not yet been demonstrated with high fidelity. Single-qubit gates in large 2D and 3D arrays have reached fidelity |${\\mathcal {F}}\\sim 0.999$| [8,10]. However, the highest demonstrated fidelity for two-qubit entanglement mediated by Rydberg-state interactions is |${\\mathcal {F}}< 0.8$| [6,14,15], a value that is well short of the theoretical limit of |${\\mathcal {F}}> 0.9999$| [16,17]. There is healthy optimism within the research community working with neutral-atom qubits that combining improved laser sources with reduced noise, better cooling to reduce motional dephasing, and control of stray electric fields that perturb Rydberg atoms will lead to substantially improved gate fidelity in the near future. Recent results with better filtering of laser phase noise have already demonstrated remarkable improvement in ground–Rydberg entanglement [18]. The outlook for the next few years appears very promising. We anticipate that with advances in lasers, optical lattices for atom trapping, deterministic rearrangement and loading of atoms in multi-dimensional arrays [19,20], and optics for fast beam scanning it will be possible to increase the number of physical qubits in a single neutral-atom module to at least 104. A challenging yet plausible path to a million-qubit processor can then be contemplated by connecting 100 such modules with atom–photon entanglement channels [21]. Beyond the potential for advancing the state of the art in computation, development of techniques for single-atom control inside large multi-atom arrays will enable other applications of quantum science including metrology and time-keeping. Rydberg interactions that are at the heart of a neutral-atom quantum computer may lead to multi-atom entanglement and Heisenberg scaling of atomic-clock precision [22]. This work was supported by the NSF and ARL CDQI.","abstract_license":"CC-BY (publisher license, via OpenAlex)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum Computing Algorithms and Architecture"],"details":null,"provenance":"openalex","attribution":"Abstract of \"Quantum computing with neutral atoms\" by Mark E. Saffman, https://doi.org/10.1093/nsr/nwy088, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified."},{"id":"arxiv:2010.07838","kind":"article","title":"Raman Sideband Cooling in Optical Tweezer Arrays for Rydberg Dressing","authors":["Nikolaus Lorenz","Lorenzo Festa","Lea-Marina Steinert","Christian Gross"],"author_count":4,"year":2020,"published":"2020-10-15","venue":"SciPost Phys. 10, 052 (2021)","cited_by":38,"doi":"10.21468/scipostphys.10.3.052","arxiv_id":"2010.07838","nct_id":null,"source_url":"https://arxiv.org/abs/2010.07838","archive_url":"https://space-kitty.com/papers/arxiv:2010.07838","updated":"2020-12-30","pmid":null,"pmcid":null,"openalex_id":"W3093358319","pdf_url":"https://arxiv.org/pdf/2010.07838","abstract":"Single neutral atoms trapped in optical tweezers and laser-coupled to Rydberg states provide a fast and flexible platform to generate configurable atomic arrays for quantum simulation. The platform is especially suited to study quantum spin systems in various geometries. However, for experiments requiring continuous trapping, inhomogeneous light shifts induced by the trapping potential and temperature broadening impose severe limitations. Here we show how Raman sideband cooling allows one to overcome those limitations, thus, preparing the stage for Rydberg dressing in tweezer arrays.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":false,"retracted":false,"peer_reviewed":null,"categories":["physics.atom-ph","quant-ph"],"details":null,"provenance":"arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1708.06387","kind":"article","title":"Coherent control of a single trapped Rydberg ion","authors":["Gerard Higgins","Fabian Pokorny","Chi Zhang","Quentin Bodart","Markus Hennrich"],"author_count":5,"year":2017,"published":"2017-08-21","venue":"Phys. Rev. Lett. 119, 220501 (2017)","cited_by":66,"doi":"10.1103/physrevlett.119.220501","arxiv_id":"1708.06387","nct_id":null,"source_url":"https://arxiv.org/abs/1708.06387","archive_url":"https://space-kitty.com/papers/arxiv:1708.06387","updated":"2017-08-21","pmid":"29286758","pmcid":null,"openalex_id":"W2749074728","pdf_url":"https://arxiv.org/pdf/1708.06387","abstract":"Trapped Rydberg ions are a promising novel approach to quantum computing and simulations. They are envisaged to combine the exquisite control of trapped ion qubits with the fast two-qubit Rydberg gates already demonstrated in neutral atom experiments. Coherent Rydberg excitation is a key requirement for these gates. Here, we carry out the first coherent Rydberg excitation of an ion and perform a single-qubit Rydberg gate, thus demonstrating basic elements of a trapped Rydberg ion quantum computer.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["quant-ph","physics.atom-ph"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2212.10159","kind":"article","title":"Robust control and optimal Rydberg states for neutral atom two-qubit gates","authors":["Madhav Mohan","Robert de Keijzer","S. J. J. M. F. Kokkelmans"],"author_count":3,"year":2023,"published":"2023-07-25","venue":"Physical Review Research","cited_by":40,"doi":"10.1103/physrevresearch.5.033052","arxiv_id":"2212.10159","nct_id":null,"source_url":"https://doi.org/10.1103/physrevresearch.5.033052","archive_url":"https://space-kitty.com/papers/arxiv:2212.10159","updated":"2023-04-21","pmid":null,"pmcid":null,"openalex_id":"W4385237588","pdf_url":"http://link.aps.org/pdf/10.1103/PhysRevResearch.5.033052","abstract":"We investigate the robustness of two-qubit gates to deviations of experimental controls, on a neutral atom platform utilizing Rydberg states. We construct robust CZ gates - employing techniques from quantum optimal control - that retain high Bell state fidelity $F > 0.999$ in the presence of significant deviations of the coupling strength to the Rydberg state. Such deviations can arise from laser intensity noise and atomic motion in an inhomogeneous coupling field. We also discuss methods to mitigate errors due to deviations of the laser detuning. The designed pulses operate on timescales that are short compared to the fundamental decay timescale set by spontaneous emission and blackbody radiation. We account for the finite lifetime of the Rydberg state in both the optimisation and fidelity calculations - this makes the gates conducive to noisy intermediate-scale quantum experiments, meaning that our protocols can reduce infidelity on near-term quantum computing devices. We calculate physical properties associated with infidelity for strontium-88 atoms - including lifetimes, polarisabilities and blockade strengths - and use these calculations to identify optimal Rydberg states for our protocols, which allows for further minimisation of infidelity.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Cold Atom Physics and Bose-Einstein Condensates"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2408.08955","kind":"article","title":"Fault-tolerant optical interconnects for neutral-atom arrays","authors":["Josiah Sinclair","Joshua Ramette","Brandon Grinkemeyer","Dolev Bluvstein","Mikhail Lukin","Vladan Vuletić"],"author_count":6,"year":2024,"published":"2024-08-16","venue":"Physical Review Research","cited_by":27,"doi":"10.1103/physrevresearch.7.013313","arxiv_id":"2408.08955","nct_id":null,"source_url":"https://arxiv.org/abs/2408.08955","archive_url":"https://space-kitty.com/papers/arxiv:2408.08955","updated":"2024-08-16","pmid":null,"pmcid":null,"openalex_id":"W4408828510","pdf_url":"https://arxiv.org/pdf/2408.08955","abstract":"We analyze the use of photonic links to enable large-scale fault-tolerant connectivity of locally error-corrected modules based on neutral atom arrays. Our approach makes use of recent theoretical results showing the robustness of surface codes to boundary noise and combines recent experimental advances in atom array quantum computing with logical qubits with optical quantum networking techniques. We find the conditions for fault-tolerance can be achieved with local two-qubit Rydberg gate and non-local Bell pair errors below 1% and 10%, respectively, without requiring distillation or space-time overheads. Realizing the interconnects with a lens, a single optical cavity, or an array of cavities enables a Bell pair generation rate in the 1-50 MHz range. When directly interfacing logical qubits, this rate translates to error-correction cycles in the 25-2000 kHz range, satisfying all requirements for fault tolerance and in the upper range fast enough for 100 kHz logical clock cycles.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["quant-ph"],"details":null,"provenance":"arxiv+openalex","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:1808.10816","kind":"preprint","title":"Quantum Optimization for Maximum Independent Set Using Rydberg Atom Arrays","authors":["Hannes Pichler","Sheng-Tao Wang","Leo Zhou","Soonwon Choi","Mikhail D. Lukin"],"author_count":5,"year":2018,"published":"2018-08-31","venue":null,"cited_by":35,"doi":null,"arxiv_id":"1808.10816","nct_id":null,"source_url":"https://arxiv.org/abs/1808.10816","archive_url":"https://space-kitty.com/papers/arxiv:1808.10816","updated":"2018-08-31","pmid":null,"pmcid":null,"openalex_id":"W4299393113","pdf_url":"https://arxiv.org/pdf/1808.10816","abstract":"We describe and analyze an architecture for quantum optimization to solve maximum independent set (MIS) problems using neutral atom arrays trapped in optical tweezers. Optimizing independent sets is one of the paradigmatic, NP-hard problems in computer science. Our approach is based on coherent manipulation of atom arrays via the excitation into Rydberg atomic states. Specifically, we show that solutions of MIS problems can be efficiently encoded in the ground state of interacting atoms in 2D arrays by utilizing the Rydberg blockade mechanism. By studying the performance of leading classical algorithms, we identify parameter regimes, where computationally hard instances can be tested using near-term experimental systems. Practical implementations of both quantum annealing and variational quantum optimization algorithms beyond the adiabatic principle are discussed.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":false,"retracted":false,"peer_reviewed":false,"categories":["quant-ph","cond-mat.quant-gas","physics.atom-ph"],"details":null,"provenance":"arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2401.04271","kind":"article","title":"Fault-Tolerant Quantum Computation Using Large Spin-Cat Codes","authors":["Sivaprasad Omanakuttan","Vikas Buchemmavari","Jonathan A. Gross","Ivan Deutsch","Milad Marvian"],"author_count":5,"year":2024,"published":"2024-06-07","venue":"PRX Quantum","cited_by":30,"doi":"10.1103/prxquantum.5.020355","arxiv_id":"2401.04271","nct_id":null,"source_url":"https://doi.org/10.1103/prxquantum.5.020355","archive_url":"https://space-kitty.com/papers/arxiv:2401.04271","updated":"2024-06-11","pmid":null,"pmcid":null,"openalex_id":"W4399432041","pdf_url":"https://arxiv.org/pdf/2401.04271","abstract":"We construct a fault-tolerant quantum error-correcting protocol based on a qubit encoded in a large spin qudit using a spin-cat code, analogous to the continuous variable cat encoding. With this, we can correct the dominant error sources, namely processes that can be expressed as error operators that are linear or quadratic in the components of angular momentum. Such codes tailored to dominant error sources {can} exhibit superior thresholds and lower resource overheads when compared to those designed for unstructured noise models. To preserve the dominant errors during gate operations, we identify a suitable universal gate set. A key component is the CNOT gate that preserves the rank of spherical tensor operators. Categorizing the dominant errors as phase and amplitude errors, we demonstrate how phase errors, analogous to phase-flip errors for qubits, can be effectively corrected. Furthermore, we propose a measurement-free error correction scheme to address amplitude errors without relying on syndrome measurements. Through an in-depth analysis of logical CNOT gate errors, we establish that the fault-tolerant threshold for error correction in the spin-cat encoding surpasses that of standard qubit-based encodings. We consider a specific implementation based on neutral-atom quantum computing, with qudits encoded in the nuclear spin of $^{87}$Sr, and show how to generate the universal gate set, including the rank-preserving CNOT gate, using quantum control and the Rydberg blockade. These findings pave the way for encoding a qubit in a large spin with the potential to achieve fault tolerance, high threshold, and reduced resource overhead in quantum information processing.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum Computing Algorithms and Architecture"],"details":null,"provenance":"openalex+arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2402.17831","kind":"article","title":"Optimal control transport of neutral atoms in optical tweezers at finite temperature","authors":["Alice Pagano","Daniel Jaschke","Werner Weiss","Simone Montangero"],"author_count":4,"year":2024,"published":"2024-02-27","venue":"Phys. Rev. Research 6, 033282 (2024)","cited_by":16,"doi":"10.1103/physrevresearch.6.033282","arxiv_id":"2402.17831","nct_id":null,"source_url":"https://arxiv.org/abs/2402.17831","archive_url":"https://space-kitty.com/papers/arxiv:2402.17831","updated":"2024-08-26","pmid":null,"pmcid":null,"openalex_id":"W4402440186","pdf_url":"https://arxiv.org/pdf/2402.17831","abstract":"The transport of neutral atoms in Rydberg quantum computers is a crucial step of the initial arrangement of the grid as well as to the dynamic connectivity, recently successfully demonstrated. We study the application of optimal control and the quantum speed limit for the transport of neutral atoms in optical tweezers at finite temperatures and analyze how laser noise affects transport fidelity. Open-loop optimal control significantly enhances transport fidelity, achieving an improvement up to $89\\%$ for the lowest analyzed temperature of $1\\,μ$K for a distance of three micrometers. Furthermore, we simulate how the transport fidelity behaves in release-and-capture measurements, which are realizable in the experiment to estimate transport efficiency and implement closed-loop optimal control.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":false,"retracted":false,"peer_reviewed":null,"categories":["quant-ph"],"details":null,"provenance":"arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."},{"id":"arxiv:2206.12385","kind":"article","title":"Spatially tunable spin interactions in neutral atom arrays","authors":["Lea-Marina Steinert","Philip Osterholz","Robin Eberhard","Lorenzo Festa","Nikolaus Lorenz","Zaijun Chen","Arno Trautmann","Christian Gross"],"author_count":8,"year":2022,"published":"2022-06-24","venue":"Phys. Rev. Lett. 130, 243001 (2023)","cited_by":49,"doi":"10.1103/physrevlett.130.243001","arxiv_id":"2206.12385","nct_id":null,"source_url":"https://arxiv.org/abs/2206.12385","archive_url":"https://space-kitty.com/papers/arxiv:2206.12385","updated":"2022-11-04","pmid":null,"pmcid":null,"openalex_id":"W4380990145","pdf_url":"https://arxiv.org/pdf/2206.12385","abstract":"Analog quantum simulations with Rydberg atoms in optical tweezers routinely address strongly correlated many-body problems due to the hardware-efficient implementation of the Hamiltonian. Yet, their generality is limited, and flexible Hamiltonian-design techniques are needed to widen the scope of these simulators. Here we report on the realization of spatially tunable interactions for XYZ models implemented by two-color near-resonant coupling to Rydberg pair states. Our results demonstrate the unique opportunities of Rydberg dressing for Hamiltonian design in analog quantum simulators.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":false,"retracted":false,"peer_reviewed":null,"categories":["physics.atom-ph","cond-mat.quant-gas","quant-ph"],"details":null,"provenance":"arxiv","attribution":"Abstract: arXiv descriptive metadata (CC0). Thank you to arXiv for use of its open access interoperability. This service was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv."}],"next":"https://space-kitty.com/api/v1/topics/atoms-and-ions/papers?sort=top&limit=25&offset=25"}