{"topic":"superconducting-qubits","sort":"top","limit":25,"offset":0,"count":25,"papers":[{"id":"arxiv:1910.11333","kind":"article","title":"Quantum supremacy using a programmable superconducting processor","authors":["Frank Arute","Kunal Arya","Ryan Babbush","Dave Bacon","Joseph C. Bardin","R. Barends","Rupak Biswas","Sergio Boixo","Fernando G. S. L. Brandão","David A. Buell","Brian Burkett","Yu Chen","Zijun Chen","Ben Chiaro","Roberto Collins","William Courtney","Andrew Dunsworth","Edward Farhi","Brooks Foxen","Austin G. Fowler","Craig Gidney","Marissa Giustina","Rob Graff","Keith Guerin","Steve Habegger"],"author_count":77,"year":2019,"published":"2019-10-23","venue":"Nature","cited_by":7735,"doi":"10.1038/s41586-019-1666-5","arxiv_id":"1910.11333","nct_id":null,"source_url":"https://doi.org/10.1038/s41586-019-1666-5","archive_url":"https://space-kitty.com/papers/arxiv:1910.11333","updated":"2019-12-28","pmid":"31645734","pmcid":null,"openalex_id":"W2982169647","pdf_url":"https://www.nature.com/articles/s41586-019-1666-5.pdf","abstract":"This is an updated version of supplementary information to accompany \"Quantum supremacy using a programmable superconducting processor\", an article published in the October 24, 2019 issue of Nature. The main article is freely available at https://www.nature.com/articles/s41586-019-1666-5. Summary of changes since arXiv:1910.11333v1 (submitted 23 Oct 2019): added URL for qFlex source code; added Erratum section; added Figure S41 comparing statistical and total uncertainty for log and linear XEB; new References [1,65]; miscellaneous updates for clarity and style consistency; miscellaneous typographical and formatting corrections.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"other-oa","is_open_access":true,"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:1704.05018","kind":"article","title":"Hardware-efficient variational quantum eigensolver for small molecules and quantum magnets","authors":["Abhinav Kandala","Antonio Mezzacapo","Kristan Temme","Maika Takita","Markus Brink","Jerry M. Chow","Jay Gambetta"],"author_count":7,"year":2017,"published":"2017-09-01","venue":"Nature","cited_by":2988,"doi":"10.1038/nature23879","arxiv_id":"1704.05018","nct_id":null,"source_url":"https://doi.org/10.1038/nature23879","archive_url":"https://space-kitty.com/papers/arxiv:1704.05018","updated":"2017-10-13","pmid":"28905916","pmcid":null,"openalex_id":"W2755255888","pdf_url":"https://arxiv.org/pdf/1704.05018","abstract":"Quantum computers can be used to address molecular structure, materials science and condensed matter physics problems, which currently stretch the limits of existing high-performance computing resources. Finding exact numerical solutions to these interacting fermion problems has exponential cost, while Monte Carlo methods are plagued by the fermionic sign problem. These limitations of classical computational methods have made even few-atom molecular structures problems of practical interest for medium-sized quantum computers. Yet, thus far experimental implementations have been restricted to molecules involving only Period I elements. Here, we demonstrate the experimental optimization of up to six-qubit Hamiltonian problems with over a hundred Pauli terms, determining the ground state energy for molecules of increasing size, up to BeH2. This is enabled by a hardware-efficient variational quantum eigensolver with trial states specifically tailored to the available interactions in our quantum processor, combined with a compact encoding of fermionic Hamiltonians and a robust stochastic optimization routine. We further demonstrate the flexibility of our approach by applying the technique to a problem of quantum magnetism. Across all studied problems, we find agreement between experiment and numerical simulations with a noisy model of the device. These results help elucidate the requirements for scaling the method to larger systems, and aim at bridging the gap between problems at the forefront of high-performance computing and their implementation on quantum hardware.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"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":"doi:10.1126/science.1231930","kind":"article","title":"Superconducting Circuits for Quantum Information: An Outlook","authors":["Michel Devoret","Robert J. Schoelkopf"],"author_count":2,"year":2013,"published":"2013-03-07","venue":"Science","cited_by":2122,"doi":"10.1126/science.1231930","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1126/science.1231930","archive_url":"https://space-kitty.com/papers/doi:10.1126/science.1231930","updated":null,"pmid":"23471399","pmcid":null,"openalex_id":"W2066500891","pdf_url":null,"abstract":null,"abstract_license":null,"license":null,"is_open_access":false,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"details":null,"provenance":"openalex","attribution":"Metadata and citation counts: OpenAlex (CC0)."},{"id":"doi:10.5281/zenodo.18067974","kind":"article","title":"Engineering Non-Linear Decay Dynamics: Pulse-Level Control and Software-Defined Qubit Rescue on Superconducting Processors","authors":["K S, Unnikuttan"],"author_count":1,"year":2025,"published":"2025-12-27","venue":"Zenodo (CERN European Organization for Nuclear Research)","cited_by":736,"doi":"10.5281/zenodo.18067974","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.5281/zenodo.18067974","archive_url":"https://space-kitty.com/papers/doi:10.5281/zenodo.18067974","updated":null,"pmid":null,"pmcid":null,"openalex_id":"W4225259930","pdf_url":null,"abstract":"The scalability of Noisy Intermediate-Scale Quantum (NISQ) devices is currently constrained by material defects, specifically Two-Level Systems (TLS) that induce resonant decoherence in superconducting qubits. This study presents a comprehensive experimental analysis using the IBM Quantum ibm_fez processor to demonstrate \"Software-Defined Hardware\" optimization. By employing a novel \"Instruction-Level Calibration Injection\" technique, we bypass standard compiler constraints to inject continuous off-resonant AC Stark drives ($N_{shots} = 4096$). Methodology The experiment utilizes a Floquet engineering approach to perform pulse-level Hamiltonian engineering. We implement custom instruction-level calibrations to apply continuous off-resonant AC Stark drives, effectively modifying the qubit frequency to avoid resonant interactions with defect states. Key Findings The application of this protocol yielded three primary results: Spectral Decoupling: Successfully restored Ramsey fringes in a defect-limited qubit (Q150), achieving a coherence time of $T_2^* \\approx 6.36 \\: \\mu\\text{s}$. Protocol Benchmarking: The \"Stark Rescue\" protocol demonstrated a statistical advantage over standard CPMG dynamical decoupling. It extended coherence time by 11.3% ($T_2^{Stark} = 8.17 \\: \\mu\\text{s}$ vs. $T_2^{CPMG} = 7.34 \\: \\mu\\text{s}$; $p = 0.042$, Bootstrap t-test). Topological Simulation: Digital simulation of a topological domain wall under engineered correlated noise revealed a sigmoidal stability threshold ($SSE \\approx 0.0008$), significantly outperforming standard exponential models ($SSE \\approx 0.0085$). Conclusion These results confirm that pulse-level Hamiltonian engineering can effectively reclaim compromised hardware resources on current NISQ platforms. Keywords NISQ, Superconducting Qubits, Two-Level Systems (TLS), Floquet Engineering, AC Stark Effect, IBM Quantum, Dynamical Decoupling, Quantum Control.","abstract_license":"CC-BY (publisher license, via OpenAlex)","license":"cc-by","is_open_access":true,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"details":null,"provenance":"openalex","attribution":"Abstract of \"Engineering Non-Linear Decay Dynamics: Pulse-Level Control and Software-Defined Qubit Rescue on Superconducting Processors\" by K S, Unnikuttan, https://doi.org/10.5281/zenodo.18067974, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified."},{"id":"doi:10.1038/s41586-023-06096-3","kind":"article","title":"Evidence for the utility of quantum computing before fault tolerance","authors":["Young‐Seok Kim","Andrew Eddins","Sajant Anand","Ken Xuan Wei","E. van den Berg","Sami Rosenblatt","Hasan M. Nayfeh","Yantao Wu","Michael P. Zaletel","Kristan Temme","Abhinav Kandala"],"author_count":11,"year":2023,"published":"2023-06-14","venue":"Nature","cited_by":1049,"doi":"10.1038/s41586-023-06096-3","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1038/s41586-023-06096-3","archive_url":"https://space-kitty.com/papers/doi:10.1038/s41586-023-06096-3","updated":null,"pmid":"37316724","pmcid":null,"openalex_id":"W4380627387","pdf_url":"https://www.nature.com/articles/s41586-023-06096-3.pdf","abstract":"Abstract Quantum computing promises to offer substantial speed-ups over its classical counterpart for certain problems. However, the greatest impediment to realizing its full potential is noise that is inherent to these systems. The widely accepted solution to this challenge is the implementation of fault-tolerant quantum circuits, which is out of reach for current processors. Here we report experiments on a noisy 127-qubit processor and demonstrate the measurement of accurate expectation values for circuit volumes at a scale beyond brute-force classical computation. We argue that this represents evidence for the utility of quantum computing in a pre-fault-tolerant era. These experimental results are enabled by advances in the coherence and calibration of a superconducting processor at this scale and the ability to characterize 1 and controllably manipulate noise across such a large device. We establish the accuracy of the measured expectation values by comparing them with the output of exactly verifiable circuits. In the regime of strong entanglement, the quantum computer provides correct results for which leading classical approximations such as pure-state-based 1D (matrix product states, MPS) and 2D (isometric tensor network states, isoTNS) tensor network methods 2,3 break down. These experiments demonstrate a foundational tool for the realization of near-term quantum applications 4,5 .","abstract_license":"CC-BY (publisher license, via OpenAlex)","license":"cc-by","is_open_access":true,"peer_reviewed":null,"categories":["Quantum Computing Algorithms and Architecture"],"details":null,"provenance":"openalex","attribution":"Abstract of \"Evidence for the utility of quantum computing before fault tolerance\" by Young‐Seok Kim, Andrew Eddins, Sajant Anand et al., https://doi.org/10.1038/s41586-023-06096-3, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified."},{"id":"doi:10.1038/nature10012","kind":"article","title":"Quantum annealing with manufactured spins","authors":["Mark W. Johnson","M. H. S. Amin","S. Gildert","Trevor M. Lanting","Firas Hamze","Neil G. Dickson","R. Harris","A. J. Berkley","J. Johansson","P. Bunyk","E. M. Chapple","Colin Enderud","Jeremy Hilton","Kamran Karimi","E. Ladizinsky","N. Ladizinsky","T. Oh","I. Perminov","C. Rich","M. C. Thom","E. Tolkacheva","C. J. S. Truncik","Sergey V. Uchaikin","J. Wang","B. Wilson"],"author_count":26,"year":2011,"published":"2011-05-01","venue":"Nature","cited_by":1893,"doi":"10.1038/nature10012","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1038/nature10012","archive_url":"https://space-kitty.com/papers/doi:10.1038/nature10012","updated":null,"pmid":"21562559","pmcid":null,"openalex_id":"W2024860775","pdf_url":null,"abstract":null,"abstract_license":null,"license":null,"is_open_access":false,"peer_reviewed":null,"categories":["Quantum Computing Algorithms and Architecture"],"details":null,"provenance":"openalex","attribution":"Metadata and citation counts: OpenAlex (CC0)."},{"id":"arxiv:1402.4848","kind":"article","title":"Superconducting quantum circuits at the surface code threshold for fault tolerance","authors":["R. Barends","J. Kelly","A. Megrant","Andrzej Veitia","D. Sank","Evan R. Jeffrey","T. White","J. Mutus","Austin G. Fowler","B. Campbell","Yanbin Chen","Z. Chen","B. Chiaro","A. Dunsworth","C. Neill","P. J. J. O’Malley","P. Roushan","A. Vainsencher","J. Wenner","Alexander N. Korotkov","Andrew N. Cleland","John M. Martinis"],"author_count":22,"year":2014,"published":"2014-04-01","venue":"Nature","cited_by":1741,"doi":"10.1038/nature13171","arxiv_id":"1402.4848","nct_id":null,"source_url":"https://doi.org/10.1038/nature13171","archive_url":"https://space-kitty.com/papers/arxiv:1402.4848","updated":"2014-02-19","pmid":"24759412","pmcid":null,"openalex_id":"W1968850365","pdf_url":"https://arxiv.org/pdf/1402.4848","abstract":"A quantum computer can solve hard problems - such as prime factoring, database searching, and quantum simulation - at the cost of needing to protect fragile quantum states from error. Quantum error correction provides this protection, by distributing a logical state among many physical qubits via quantum entanglement. Superconductivity is an appealing platform, as it allows for constructing large quantum circuits, and is compatible with microfabrication. For superconducting qubits the surface code is a natural choice for error correction, as it uses only nearest-neighbour coupling and rapidly-cycled entangling gates. The gate fidelity requirements are modest: The per-step fidelity threshold is only about 99%. Here, we demonstrate a universal set of logic gates in a superconducting multi-qubit processor, achieving an average single-qubit gate fidelity of 99.92% and a two-qubit gate fidelity up to 99.4%. This places Josephson quantum computing at the fault-tolerant threshold for surface code error correction. Our quantum processor is a first step towards the surface code, using five qubits arranged in a linear array with nearest-neighbour coupling. As a further demonstration, we construct a five-qubit Greenberger-Horne-Zeilinger (GHZ) state using the complete circuit and full set of gates. The results demonstrate that Josephson quantum computing is a high-fidelity technology, with a clear path to scaling up to large-scale, fault-tolerant quantum circuits.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"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:1006.4395","kind":"article","title":"Non-Abelian statistics and topological quantum information processing in 1D wire networks","authors":["Jason Alicea","Yuval Oreg A","Gil Refael","Felix von Oppen","Matthew P. A. Fisher"],"author_count":5,"year":2011,"published":"2011-02-13","venue":"Nature Physics","cited_by":1637,"doi":"10.1038/nphys1915","arxiv_id":"1006.4395","nct_id":null,"source_url":"https://doi.org/10.1038/nphys1915","archive_url":"https://space-kitty.com/papers/arxiv:1006.4395","updated":"2010-09-19","pmid":null,"pmcid":null,"openalex_id":"W2153852402","pdf_url":"https://arxiv.org/pdf/1006.4395","abstract":"Topological quantum computation provides an elegant way around decoherence, as one encodes quantum information in a non-local fashion that the environment finds difficult to corrupt. Here we establish that one of the key operations---braiding of non-Abelian anyons---can be implemented in one-dimensional semiconductor wire networks. Previous work [Lutchyn et al., arXiv:1002.4033 and Oreg et al., arXiv:1003.1145] provided a recipe for driving semiconducting wires into a topological phase supporting long-sought particles known as Majorana fermions that can store topologically protected quantum information. Majorana fermions in this setting can be transported, created, and fused by applying locally tunable gates to the wire. More importantly, we show that networks of such wires allow braiding of Majorana fermions and that they exhibit non-Abelian statistics like vortices in a p+ip superconductor. We propose experimental setups that enable the Majorana fusion rules to be probed, along with networks that allow for efficient exchange of arbitrary numbers of Majorana fermions. This work paves a new path forward in topological quantum computation that benefits from physical transparency and experimental realism.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"peer_reviewed":null,"categories":["Topological Materials and Phenomena"],"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:2408.13687","kind":"article","title":"Quantum error correction below the surface code threshold","authors":["Rajeev Acharya","Laleh Aghababaie-Beni","Igor Aleiner","Trond I. Andersen","Markus Ansmann","Frank Arute","Kunal Arya","Abraham Asfaw","Nikita Astrakhantsev","Juan Atalaya","Ryan Babbush","Dave Bacon","Brian Ballard","Joseph C. Bardin","Johannes Bausch","Andreas Bengtsson","Alexander Bilmes","Sam Blackwell","Sergio Boixo","Gina Bortoli","Alexandre Bourassa","Jenna Bovaird","Leon Brill","Michael Broughton","David A. Browne"],"author_count":249,"year":2024,"published":"2024-08-24","venue":"Nature 638 (2025) 920-926","cited_by":774,"doi":"10.1038/s41586-024-08449-y","arxiv_id":"2408.13687","nct_id":null,"source_url":"https://arxiv.org/abs/2408.13687","archive_url":"https://space-kitty.com/papers/arxiv:2408.13687","updated":"2024-08-24","pmid":"39653125","pmcid":null,"openalex_id":"W4405183524","pdf_url":"https://arxiv.org/pdf/2408.13687","abstract":"Quantum error correction provides a path to reach practical quantum computing by combining multiple physical qubits into a logical qubit, where the logical error rate is suppressed exponentially as more qubits are added. However, this exponential suppression only occurs if the physical error rate is below a critical threshold. In this work, we present two surface code memories operating below this threshold: a distance-7 code and a distance-5 code integrated with a real-time decoder. The logical error rate of our larger quantum memory is suppressed by a factor of $Λ$ = 2.14 $\\pm$ 0.02 when increasing the code distance by two, culminating in a 101-qubit distance-7 code with 0.143% $\\pm$ 0.003% error per cycle of error correction. This logical memory is also beyond break-even, exceeding its best physical qubit's lifetime by a factor of 2.4 $\\pm$ 0.3. We maintain below-threshold performance when decoding in real time, achieving an average decoder latency of 63 $μ$s at distance-5 up to a million cycles, with a cycle time of 1.1 $μ$s. To probe the limits of our error-correction performance, we run repetition codes up to distance-29 and find that logical performance is limited by rare correlated error events occurring approximately once every hour, or 3 $\\times$ 10$^9$ cycles. Our results present device performance that, if scaled, could realize the operational requirements of large scale fault-tolerant quantum algorithms.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by-nc-nd","is_open_access":true,"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:2106.14734","kind":"article","title":"Strong Quantum Computational Advantage Using a Superconducting Quantum Processor","authors":["Yulin Wu","Wan‐Su Bao","Sirui Cao","Fusheng Chen","Ming-Cheng Chen","Xiawei Chen","Tung-Hsun Chung","Huiqiu Deng","Yajie Du","Daojin Fan","Ming Gong","Cheng Guo","Chu Guo","Shaojun Guo","Lianchen Han","Linyin Hong","He-Liang Huang","Yong-Heng Huo","Liping Li","Na Li","Shaowei Li","Yuan Li","Futian Liang","Chun Hao Lin","Jin Lin"],"author_count":54,"year":2021,"published":"2021-10-25","venue":"Physical Review Letters","cited_by":1058,"doi":"10.1103/physrevlett.127.180501","arxiv_id":"2106.14734","nct_id":null,"source_url":"https://doi.org/10.1103/physrevlett.127.180501","archive_url":"https://space-kitty.com/papers/arxiv:2106.14734","updated":"2021-06-28","pmid":"34767433","pmcid":null,"openalex_id":"W3173899054","pdf_url":"https://arxiv.org/pdf/2106.14734","abstract":"Scaling up to a large number of qubits with high-precision control is essential in the demonstrations of quantum computational advantage to exponentially outpace the classical hardware and algorithmic improvements. Here, we develop a two-dimensional programmable superconducting quantum processor, \\textit{Zuchongzhi}, which is composed of 66 functional qubits in a tunable coupling architecture. To characterize the performance of the whole system, we perform random quantum circuits sampling for benchmarking, up to a system size of 56 qubits and 20 cycles. The computational cost of the classical simulation of this task is estimated to be 2-3 orders of magnitude higher than the previous work on 53-qubit Sycamore processor [Nature \\textbf{574}, 505 (2019)]. We estimate that the sampling task finished by \\textit{Zuchongzhi} in about 1.2 hours will take the most powerful supercomputer at least 8 years. Our work establishes an unambiguous quantum computational advantage that is infeasible for classical computation in a reasonable amount of time. The high-precision and programmable quantum computing platform opens a new door to explore novel many-body phenomena and implement complex quantum algorithms.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"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:1003.2376","kind":"article","title":"Circuit quantum electrodynamics in the ultrastrong-coupling regime","authors":["T. Niemczyk","Frank Deppe","Hans Huebl","E. P. Menzel","Fredrik Hocke","M. J. Schwarz","Juan José García‐Ripoll","David Zueco","Thomas Hümmer","E. Solano","Achim Marx","R. Gross"],"author_count":12,"year":2010,"published":"2010-07-25","venue":"Nature Physics","cited_by":1324,"doi":"10.1038/nphys1730","arxiv_id":"1003.2376","nct_id":null,"source_url":"https://doi.org/10.1038/nphys1730","archive_url":"https://space-kitty.com/papers/arxiv:1003.2376","updated":"2010-03-11","pmid":null,"pmcid":null,"openalex_id":"W2056576695","pdf_url":"https://www.nature.com/articles/nphys1730.pdf","abstract":"In cavity quantum electrodynamics (QED), light-matter interaction is probed at its most fundamental level, where individual atoms are coupled to single photons stored in three-dimensional cavities. This unique possibility to experimentally explore the foundations of quantum physics has greatly evolved with the advent of circuit QED, where on-chip superconducting qubits and oscillators play the roles of two-level atoms and cavities, respectively. In the strong coupling limit, atom and cavity can exchange a photon frequently before coherence is lost. This important regime has been reached both in cavity and circuit QED, but the design flexibility and engineering potential of the latter allowed for increasing the ratio between the atom-cavity coupling rate and the cavity transition frequency above the percent level. While these experiments are well described by the renowned Jaynes-Cummings model, novel physics is expected in the ultrastrong coupling limit. Here, we report on the first experimental realization of a superconducting circuit QED system in the ultrastrong coupling limit and present direct evidence for the breakdown of the Jaynes-Cummings model.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"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:1610.02208","kind":"article","title":"Quantum information processing with superconducting circuits: a review","authors":["Goran P. Wendin"],"author_count":1,"year":2017,"published":"2017-07-06","venue":"Reports on Progress in Physics","cited_by":977,"doi":"10.1088/1361-6633/aa7e1a","arxiv_id":"1610.02208","nct_id":null,"source_url":"https://doi.org/10.1088/1361-6633/aa7e1a","archive_url":"https://space-kitty.com/papers/arxiv:1610.02208","updated":"2017-10-08","pmid":"28682303","pmcid":null,"openalex_id":"W2530095757","pdf_url":"https://iopscience.iop.org/article/10.1088/1361-6633/aa7e1a/pdf","abstract":"During the last ten years, superconducting circuits have passed from being interesting physical devices to becoming contenders for near-future useful and scalable quantum information processing (QIP). Advanced quantum simulation experiments have been shown with up to nine qubits, while a demonstration of Quantum Supremacy with fifty qubits is anticipated in just a few years. Quantum Supremacy means that the quantum system can no longer be simulated by the most powerful classical supercomputers. Integrated classical-quantum computing systems are already emerging that can be used for software development and experimentation, even via web interfaces. Therefore, the time is ripe for describing some of the recent development of superconducting devices, systems and applications. As such, the discussion of superconducting qubits and circuits is limited to devices that are proven useful for current or near future applications. Consequently, the centre of interest is the practical applications of QIP, such as computation and simulation in Physics and Chemistry.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by-sa","is_open_access":true,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"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":"doi:10.1038/nature18949","kind":"article","title":"Extending the lifetime of a quantum bit with error correction in superconducting circuits","authors":["Nissim Ofek","Andrei Petrenko","Reinier Heeres","Philip Reinhold","Zaki Leghtas","Brian Vlastakis","Yehan Liu","Luigi Frunzio","S. M. Girvin","Liang Jiang","Mazyar Mirrahimi","Michel Devoret","Robert J. Schoelkopf"],"author_count":13,"year":2016,"published":"2016-07-19","venue":"Nature","cited_by":944,"doi":"10.1038/nature18949","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1038/nature18949","archive_url":"https://space-kitty.com/papers/doi:10.1038/nature18949","updated":null,"pmid":"27437573","pmcid":null,"openalex_id":"W2502126115","pdf_url":null,"abstract":null,"abstract_license":null,"license":null,"is_open_access":false,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"details":null,"provenance":"openalex","attribution":"Metadata and citation counts: OpenAlex (CC0)."},{"id":"arxiv:1805.04492","kind":"article","title":"Error mitigation extends the computational reach of a noisy quantum processor","authors":["Abhinav Kandala","Kristan Temme","Antonio D. Corcoles","Antonio Mezzacapo","Jerry M. Chow","Jay Gambetta"],"author_count":6,"year":2019,"published":"2019-03-01","venue":"Nature","cited_by":875,"doi":"10.1038/s41586-019-1040-7","arxiv_id":"1805.04492","nct_id":null,"source_url":"https://doi.org/10.1038/s41586-019-1040-7","archive_url":"https://space-kitty.com/papers/arxiv:1805.04492","updated":"2018-05-11","pmid":"30918370","pmcid":null,"openalex_id":"W2923370183","pdf_url":"https://arxiv.org/pdf/1805.04492","abstract":"Quantum computation, a completely different paradigm of computing, benefits from theoretically proven speed-ups for certain problems and opens up the possibility of exactly studying the properties of quantum systems. Yet, because of the inherent fragile nature of the physical computing elements, qubits, achieving quantum advantages over classical computation requires extremely low error rates for qubit operations as well as a significant overhead of physical qubits, in order to realize fault-tolerance via quantum error correction. However, recent theoretical work has shown that the accuracy of computation based off expectation values of quantum observables can be enhanced through an extrapolation of results from a collection of varying noisy experiments. Here, we demonstrate this error mitigation protocol on a superconducting quantum processor, enhancing its computational capability, with no additional hardware modifications. We apply the protocol to mitigate errors on canonical single- and two-qubit experiments and then extend its application to the variational optimization of Hamiltonians for quantum chemistry and magnetism. We effectively demonstrate that the suppression of incoherent errors helps unearth otherwise inaccessible accuracies to the variational solutions using our noisy processor. These results demonstrate that error mitigation techniques will be critical to significantly enhance the capabilities of near-term quantum computing hardware.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"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:2004.04174","kind":"article","title":"Hartree-Fock on a superconducting qubit quantum computer","authors":["Google AI Quantum and Collaborators","Frank Arute","Kunal Arya","Ryan Babbush","Dave Bacon","Joseph C. Bardin","R. Barends","Sergio Boixo","Michael Broughton","Bob B. Buckley","David A. Buell","Brian Burkett","Nicholas Bushnell","Yu Chen","Zijun Chen","Benjamin Chiaro","Roberto Collins","William Courtney","Sean Demura","Andrew Dunsworth","Edward Farhi","Austin G. Fowler","Brooks Foxen","Craig Gidney","Marissa Giustina"],"author_count":82,"year":2020,"published":"2020-08-28","venue":"Science","cited_by":830,"doi":"10.1126/science.abb9811","arxiv_id":"2004.04174","nct_id":null,"source_url":"https://doi.org/10.1126/science.abb9811","archive_url":"https://space-kitty.com/papers/arxiv:2004.04174","updated":"2020-09-18","pmid":"32855334","pmcid":null,"openalex_id":"W3015289174","pdf_url":"https://arxiv.org/pdf/2004.04174","abstract":"As the search continues for useful applications of noisy intermediate scale quantum devices, variational simulations of fermionic systems remain one of the most promising directions. Here, we perform a series of quantum simulations of chemistry the largest of which involved a dozen qubits, 78 two-qubit gates, and 114 one-qubit gates. We model the binding energy of ${\\rm H}_6$, ${\\rm H}_8$, ${\\rm H}_{10}$ and ${\\rm H}_{12}$ chains as well as the isomerization of diazene. We also demonstrate error-mitigation strategies based on $N$-representability which dramatically improve the effective fidelity of our experiments. Our parameterized ansatz circuits realize the Givens rotation approach to non-interacting fermion evolution, which we variationally optimize to prepare the Hartree-Fock wavefunction. This ubiquitous algorithmic primitive corresponds to a rotation of the orbital basis and is required by many proposals for correlated simulations of molecules and Hubbard models. Because non-interacting fermion evolutions are classically tractable to simulate, yet still generate highly entangled states over the computational basis, we use these experiments to benchmark the performance of our hardware while establishing a foundation for scaling up more complex correlated quantum simulations of chemistry.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"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":"doi:10.1126/science.aaa3693","kind":"article","title":"Coherent coupling between a ferromagnetic magnon and a superconducting qubit","authors":["Yutaka Tabuchi","Seiichiro Ishino","Atsushi Noguchi","T. Ishikawa","Rekishu Yamazaki","Koji Usami","Yasunobu Nakamura"],"author_count":7,"year":2015,"published":"2015-07-10","venue":"Science","cited_by":909,"doi":"10.1126/science.aaa3693","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1126/science.aaa3693","archive_url":"https://space-kitty.com/papers/doi:10.1126/science.aaa3693","updated":null,"pmid":"26160378","pmcid":null,"openalex_id":"W1520835611","pdf_url":null,"abstract":null,"abstract_license":null,"license":null,"is_open_access":false,"peer_reviewed":null,"categories":["Mechanical and Optical Resonators"],"details":null,"provenance":"openalex","attribution":"Metadata and citation counts: OpenAlex (CC0)."},{"id":"arxiv:1902.03024","kind":"article","title":"Hybrid quantum systems based on magnonics","authors":["Dany Lachance-Quirion","Yutaka Tabuchi","A. Gloppe","Koji Usami","Yasunobu Nakamura"],"author_count":5,"year":2019,"published":"2019-05-24","venue":"Applied Physics Express","cited_by":779,"doi":"10.7567/1882-0786/ab248d","arxiv_id":"1902.03024","nct_id":null,"source_url":"https://doi.org/10.7567/1882-0786/ab248d","archive_url":"https://space-kitty.com/papers/arxiv:1902.03024","updated":"2019-02-21","pmid":null,"pmcid":null,"openalex_id":"W2913069042","pdf_url":"https://iopscience.iop.org/article/10.7567/1882-0786/ab248d/pdf","abstract":"Engineered quantum systems enabling novel capabilities for communication, computation, and sensing have blossomed in the last decade. Architectures benefiting from combining distinct and complementary physical quantum systems have emerged as promising platforms for developing quantum technologies. A new class of hybrid quantum systems based on collective spin excitations in ferromagnetic materials has led to the diverse set of experimental platforms which are outlined in this review article. The coherent interaction between microwave cavity modes and collective spin-wave modes is presented as the backbone of the development of more complex hybrid quantum systems. Indeed, quanta of excitation of the spin-wave modes, called magnons, can also interact coherently with optical photons, phonons, and superconducting qubits in the fields of cavity optomagnonics, cavity magnomechanics, and quantum magnonics, respectively. Notably, quantum magnonics provides a promising platform for performing quantum optics experiments in magnetically-ordered solid-state systems. Applications of hybrid quantum systems based on magnonics for quantum information processing and quantum sensing are also outlined briefly.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"peer_reviewed":null,"categories":["Mechanical and Optical Resonators"],"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:2112.03708","kind":"article","title":"Realizing Repeated Quantum Error Correction in a Distance-Three Surface Code","authors":["Sebastian Krinner","Nathan Lacroix","Ants Remm","Agustin Di Paolo","Elie Genois","Catherine Leroux","Christoph Hellings","Stefania Lazar","Francois Swiadek","Johannes Herrmann","Graham J. Norris","Christian Kraglund Andersen","Markus Müller","Alexandre Blais","Christopher Eichler","Andreas Wallraff"],"author_count":16,"year":2021,"published":"2021-12-07","venue":"Nature 605, 669 (2022)","cited_by":686,"doi":"10.1038/s41586-022-04566-8","arxiv_id":"2112.03708","nct_id":null,"source_url":"https://arxiv.org/abs/2112.03708","archive_url":"https://space-kitty.com/papers/arxiv:2112.03708","updated":"2021-12-07","pmid":"35614249","pmcid":null,"openalex_id":"W4200634137","pdf_url":"https://arxiv.org/pdf/2112.03708","abstract":"Quantum computers hold the promise of solving computational problems which are intractable using conventional methods. For fault-tolerant operation quantum computers must correct errors occurring due to unavoidable decoherence and limited control accuracy. Here, we demonstrate quantum error correction using the surface code, which is known for its exceptionally high tolerance to errors. Using 17 physical qubits in a superconducting circuit we encode quantum information in a distance-three logical qubit building up on recent distance-two error detection experiments. In an error correction cycle taking only $1.1\\,μ$s, we demonstrate the preservation of four cardinal states of the logical qubit. Repeatedly executing the cycle, we measure and decode both bit- and phase-flip error syndromes using a minimum-weight perfect-matching algorithm in an error-model-free approach and apply corrections in postprocessing. We find a low error probability of $3\\,\\%$ per cycle when rejecting experimental runs in which leakage is detected. The measured characteristics of our device agree well with a numerical model. Our demonstration of repeated, fast and high-performance quantum error correction cycles, together with recent advances in ion traps, support our understanding that fault-tolerant quantum computation will be practically realizable.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"peer_reviewed":null,"categories":["quant-ph","cond-mat.mes-hall"],"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:2111.14241","kind":"article","title":"Quantum magnonics: When magnon spintronics meets quantum information science","authors":["H. Y. Yuan","Yunshan Cao","Akashdeep Kamra","R. A. Duine","Peng Yan"],"author_count":5,"year":2022,"published":"2022-04-25","venue":"Physics Reports","cited_by":616,"doi":"10.1016/j.physrep.2022.03.002","arxiv_id":"2111.14241","nct_id":null,"source_url":"https://doi.org/10.1016/j.physrep.2022.03.002","archive_url":"https://space-kitty.com/papers/arxiv:2111.14241","updated":"2022-03-23","pmid":null,"pmcid":null,"openalex_id":"W3217066553","pdf_url":"https://arxiv.org/pdf/2111.14241","abstract":"Spintronics and quantum information science are two promising candidates for innovating information processing technologies. The combination of these two fields enables us to build solid-state platforms for studying quantum phenomena and for realizing multi-functional quantum tasks. For a long time, however, the intersection of these two fields was limited. This situation has changed significantly over the last few years because of the remarkable progress in coding and processing information using magnons. On the other hand, significant advances in understanding the entanglement of quasi-particles and in designing high-quality qubits and photonic cavities for quantum information processing provide physical platforms to integrate magnons with quantum systems. From these endeavours, the highly interdisciplinary field of quantum magnonics emerges, which combines spintronics, quantum optics and quantum information science.Here, we give an overview of the recent developments concerning the quantum states of magnons and their hybridization with mature quantum platforms. First, we review the basic concepts of magnons and quantum entanglement and discuss the generation and manipulation of quantum states of magnons, such as single-magnon states, squeezed states and quantum many-body states including Bose-Einstein condensation and the resulting spin superfluidity. We discuss how magnonic systems can be integrated and entangled with quantum platforms including cavity photons, superconducting qubits, nitrogen-vacancy centers, and phonons for coherent information transfer and collaborative information processing. The implications of these hybrid quantum systems for non-Hermitian physics and parity-time symmetry are highlighted, together with applications in quantum memories and high-precision measurements. Finally, we present an outlook on the opportunities in quantum magnonics.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"peer_reviewed":null,"categories":["Mechanical and Optical Resonators"],"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:2103.08578","kind":"article","title":"Millisecond coherence in a superconducting qubit","authors":["Aaron Somoroff","Quentin Ficheux","Raymond A. Mencia","Haonan Xiong","Roman V. Kuzmin","Vladimir E. Manucharyan"],"author_count":6,"year":2021,"published":"2021-03-15","venue":"Physical Review Letters","cited_by":236,"doi":"10.1103/physrevlett.130.267001","arxiv_id":"2103.08578","nct_id":null,"source_url":"https://arxiv.org/abs/2103.08578","archive_url":"https://space-kitty.com/papers/arxiv:2103.08578","updated":"2021-03-15","pmid":"37450803","pmcid":null,"openalex_id":"W3138004811","pdf_url":"https://arxiv.org/pdf/2103.08578","abstract":"Increasing the degree of control over physical qubits is a crucial component of quantum computing research. We report a superconducting qubit of fluxonium type with the Ramsey coherence time reaching $T_2^*= 1.48 \\pm 0.13 \\mathrm{~ms}$, which exceeds the state of the art value by an order of magnitude. As a result, the average single-qubit gate fidelity grew above $0.9999$, surpassing, to our knowledge, any other solid-state quantum system. Furthermore, by measuring energy relaxation of the parity-forbidden transition to second excited state, we exclude the effect of out-of-equilibrium quasiparticles on coherence in our circuit. Combined with recent demonstrations of two-qubit gates on fluxoniums, our result paves the way for the next generation of quantum processors.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"peer_reviewed":null,"categories":["quant-ph","cond-mat.mes-hall","cond-mat.supr-con"],"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:1105.3772","kind":"article","title":"Electron spin coherence exceeding seconds in high-purity silicon","authors":["Alexei M. Tyryshkin","Shinichi Tojo","John J. L. Morton","Helge P. Riemann","Nikolai V. Abrosimov","Peter Becker","Hans-Joachim Pohl","Thomas Schenkel","Michael L. W. Thewalt","Kohei M. Itoh","S. A. Lyon"],"author_count":11,"year":2011,"published":"2011-12-01","venue":"Nature Materials","cited_by":717,"doi":"10.1038/nmat3182","arxiv_id":"1105.3772","nct_id":null,"source_url":"https://doi.org/10.1038/nmat3182","archive_url":"https://space-kitty.com/papers/arxiv:1105.3772","updated":"2011-05-19","pmid":"22138791","pmcid":null,"openalex_id":"W2152120788","pdf_url":"https://arxiv.org/pdf/1105.3772","abstract":"Silicon is undoubtedly one of the most promising semiconductor materials for spin-based information processing devices. Its highly advanced fabrication technology facilitates the transition from individual devices to large-scale processors, and the availability of an isotopically-purified $^{28}$Si form with no magnetic nuclei overcomes what is a main source of spin decoherence in many other materials. Nevertheless, the coherence lifetimes of electron spins in the solid state have typically remained several orders of magnitude lower than what can be achieved in isolated high-vacuum systems such as trapped ions. Here we examine electron spin coherence of donors in very pure $^{28}$Si material, with a residual $^{29}$Si concentration of less than 50 ppm and donor densities of $10^{14-15}$ per cm$^3$. We elucidate three separate mechanisms for spin decoherence, active at different temperatures, and extract a coherence lifetime $T_2$ up to 2 seconds. In this regime, we find the electron spin is sensitive to interactions with other donor electron spins separated by ~200 nm. We apply a magnetic field gradient in order to suppress such interactions and obtain an extrapolated electron spin $T_2$ of 10 seconds at 1.8 K. These coherence lifetimes are without peer in the solid state by several orders of magnitude and comparable with high-vacuum qubits, making electron spins of donors in silicon ideal components of a quantum computer, or quantum memories for systems such as superconducting qubits.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"peer_reviewed":null,"categories":["Quantum and electron transport phenomena"],"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":"doi:10.1038/s41578-019-0136-x","kind":"review","title":"2D materials for quantum information science","authors":["Xiaolong Liu","Mark C. Hersam"],"author_count":2,"year":2019,"published":"2019-08-19","venue":"Nature Reviews Materials","cited_by":643,"doi":"10.1038/s41578-019-0136-x","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1038/s41578-019-0136-x","archive_url":"https://space-kitty.com/papers/doi:10.1038/s41578-019-0136-x","updated":null,"pmid":null,"pmcid":null,"openalex_id":"W2969694507","pdf_url":null,"abstract":null,"abstract_license":null,"license":null,"is_open_access":false,"peer_reviewed":null,"categories":["2D Materials and Applications"],"details":null,"provenance":"openalex","attribution":"Metadata and citation counts: OpenAlex (CC0)."},{"id":"arxiv:1002.1871","kind":"article","title":"Natural and artificial atoms for quantum computation","authors":["I. M. Buluta","Sahel Ashhab","Franco Nori"],"author_count":3,"year":2011,"published":"2011-09-19","venue":"Reports on Progress in Physics","cited_by":694,"doi":"10.1088/0034-4885/74/10/104401","arxiv_id":"1002.1871","nct_id":null,"source_url":"https://doi.org/10.1088/0034-4885/74/10/104401","archive_url":"https://space-kitty.com/papers/arxiv:1002.1871","updated":"2011-08-23","pmid":null,"pmcid":null,"openalex_id":"W2127595774","pdf_url":"https://iopscience.iop.org/article/10.1088/0034-4885/74/10/104401/pdf","abstract":"Remarkable progress towards realizing quantum computation has been achieved using natural and artificial atoms as qubits. This article presents a brief overview of the current status of different types of qubits. On the one hand, natural atoms (such as neutral atoms and ions) have long coherence times, and could be stored in large arrays, providing ideal \"quantum memories\". On the other hand, artificial atoms (such as superconducting circuits or semiconductor quantum dots) have the advantage of custom-designed features and could be used as \"quantum processing units\". Natural and artificial atoms can be coupled with each other and can also be interfaced with photons for long-distance communications. Hybrid devices made of natural/artificial atoms and photons may provide the next-generation design for quantum computers.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":null,"is_open_access":true,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"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":"doi:10.1126/science.1243289","kind":"article","title":"Deterministically Encoding Quantum Information Using 100-Photon Schrödinger Cat States","authors":["Brian Vlastakis","Gerhard Kirchmair","Zaki Leghtas","Simon E. Nigg","Luigi Frunzio","S. M. Girvin","Mazyar Mirrahimi","Michel Devoret","Robert J. Schoelkopf"],"author_count":9,"year":2013,"published":"2013-09-27","venue":"Science","cited_by":643,"doi":"10.1126/science.1243289","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1126/science.1243289","archive_url":"https://space-kitty.com/papers/doi:10.1126/science.1243289","updated":null,"pmid":"24072821","pmcid":null,"openalex_id":"W1970935766","pdf_url":null,"abstract":null,"abstract_license":null,"license":null,"is_open_access":false,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"details":null,"provenance":"openalex","attribution":"Metadata and citation counts: OpenAlex (CC0)."},{"id":"arxiv:2003.00024","kind":"article","title":"New material platform for superconducting transmon qubits with coherence times exceeding 0.3 milliseconds","authors":["Alexander P. M. Place","Lila V. H. Rodgers","Pranav Mundada","Basil M. Smitham","Mattias Fitzpatrick","Zhaoqi Leng","Anjali Premkumar","Jacob Bryon","Andrei Vrajitoarea","Sara Sussman","Guangming Cheng","Trisha Madhavan","Harshvardhan K. Babla","Xuan Hoang Le","Youqi Gang","Berthold Jäck","András Gyenis","Nan Yao","R. J. Cava","Nathalie P. de Leon","Andrew Houck"],"author_count":21,"year":2021,"published":"2021-03-19","venue":"Nature Communications","cited_by":564,"doi":"10.1038/s41467-021-22030-5","arxiv_id":"2003.00024","nct_id":null,"source_url":"https://doi.org/10.1038/s41467-021-22030-5","archive_url":"https://space-kitty.com/papers/arxiv:2003.00024","updated":"2020-02-28","pmid":"33741989","pmcid":null,"openalex_id":"W3006932841","pdf_url":"https://www.nature.com/articles/s41467-021-22030-5.pdf","abstract":"The superconducting transmon qubit is a leading platform for quantum computing and quantum science. Building large, useful quantum systems based on transmon qubits will require significant improvements in qubit relaxation and coherence times, which are orders of magnitude shorter than limits imposed by bulk properties of the constituent materials. This indicates that relaxation likely originates from uncontrolled surfaces, interfaces, and contaminants. Previous efforts to improve qubit lifetimes have focused primarily on designs that minimize contributions from surfaces. However, significant improvements in the lifetime of two-dimensional transmon qubits have remained elusive for several years. Here, we fabricate two-dimensional transmon qubits that have both lifetimes and coherence times with dynamical decoupling exceeding 0.3 milliseconds by replacing niobium with tantalum in the device. We have observed increased lifetimes for seventeen devices, indicating that these material improvements are robust, paving the way for higher gate fidelities in multi-qubit processors.","abstract_license":"CC0-1.0 (arXiv descriptive metadata)","license":"cc-by","is_open_access":true,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"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."}],"next":"https://space-kitty.com/api/v1/topics/superconducting-qubits/papers?sort=top&limit=25&offset=25"}