Realization of high-fidelity CZ and ZZ-free iSWAP gates with a tunable coupler
Youngkyu Sung, Leon Ding, Jochen Braumüller, Antti Vepsäläinen, Bharath Kannan, Morten Kjaergaard, Ami Greene, Gabriel O. Samach, Chris McNally, David Kim, Alex… 展开作者
Youngkyu Sung, Leon Ding, Jochen Braumüller, Antti Vepsäläinen, Bharath Kannan, Morten Kjaergaard, Ami Greene, Gabriel O. Samach, Chris McNally, David Kim, Alexander Melville, Bethany M. Niedzielski, Mollie E. Schwartz, Jonilyn L. Yoder, Terry P. Orlando, Simon Gustavsson, William D. Oliver
High-fidelity two-qubit gates at scale are a key requirement to realize the full promise of quantum computation and simulation. The advent and use of coupler elements to tunably control two-qubit interactions has improved operational fidelity in many-qubit systems by reducing parasitic coupling and frequency crowding issues. Nonetheless, two-qubit gate errors still limit the capability of near-term quantum applications. The reason, in part, is the existing framework for tunable couplers based on the dispersive approximation does not fully incorporate three-body multi-level dynamics, which is essential for addressing coherent leakage to the coupler and parasitic longitudinal ($ZZ$) interactions during two-qubit gates. Here, we present a systematic approach that goes beyond the dispersive approximation to exploit the engineered level structure of the coupler and optimize its control. Using this approach, we experimentally demonstrate CZ and $ZZ$-free iSWAP gates with two-qubit interaction fidelities of $99.76 \pm 0.07$% and $99.87 \pm 0.23$%, respectively, which are close to their $T_1$ limits.
High-fidelity iSWAP gate with Double Transmon Coupler
University of Massachusetts, Lowell（马萨诸塞大学洛厄尔分校）；RTX BBN Technologies（RTX BBN科技公司）；University of Colorado, Boulder（科罗拉多大学博尔德分校）；National Institute of Standards and Technology（美国国家标准与技术研究院）；Air Force Research Laboratory（空军研究实验室）；Northwestern University（西北大学）
Parametrically Driven iSWAP Gate Using a Capacitively Shunted Double-Transmon Coupler at the Zero-Flux Sweet Spot
RIKEN Center for Quantum Computing (RQC)（理化学研究所量子计算中心）；Department of Applied Physics, Graduate School of Engineering, The University of Tokyo（东京大学大学院工学研究科应用物理系）；Corporate Laboratory, Toshiba Corporation（东芝公司企业实验室）
Simple analytical flux-tuned iSWAP pulses for leakage suppression
Institute for Quantum Control (PGI-8), Forschungszentrum Jülich（于利希研究中心量子控制研究所）；Institute for Theoretical Physics, University of Cologne（科隆大学理论物理研究所）；Institute for Functional Quantum System (PGI-13), Forschungszentrum Jülich（于利希研究中心功能量子系统研究所）；Department of Physics, RWTH Aachen University（亚琛工业大学物理系）
Optimizing the frequency positioning of tunable couplers in a circuit QED processor to mitigate spectator effects on quantum operations
QuTech and Kavli Institute of Nanoscience, Delft University of Technology（代尔夫特理工大学奎克与卡弗里纳米科学研究所）；Orange Quantum Systems（橙量子系统）；Quantware B.V.（Quantware有限公司）
Tunable Hybrid-Mode Coupler Enabling Strong Interactions between Transmons at Centimeter-Scale Distance
National Laboratory of Solid State Microstructures, School of Physics, Nanjing University（南京大学固体微结构物理学院）；Shishan Laboratory, Nanjing University（南京大学苏州校区）；Jiangsu Key Laboratory of Quantum Information Science and Technology, Nanjing University（南京大学量子信息科学与技术江苏省重点实验室）
Breaking the scalability barrier via a vertical tunable coupler in 3D integrated transmon system
National Laboratory of Solid State Microstructures, School of Physics, Nanjing University（南京大学固体微结构物理学院）；Shishan Laboratory, Nanjing University（南京大学时山实验室）；Jiangsu Key Laboratory of Ouantum Information Science and Technology, Nanjing University（南京大学江苏省量子信息科学与技术重点实验室）；Tencent Quantum Laboratory, Tencent（腾讯量子实验室）
A cavity-mediated reconfigurable coupling scheme for superconducting qubits
Pritzker School of Molecular Engineering, University of Chicago（芝加哥大学普里茨克分子工程学院）；Institute of Applied Physics, Seoul National University（首尔国立大学应用物理研究所）；NextQuantum Innovation Research Center, Seoul National University（首尔国立大学NextQuantum创新中心）；Department of Physics and Astronomy, Seoul National University（首尔国立大学物理与天文学系）
Long-range tunable coupler for modular fluxonium quantum processors
Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area（粤港澳大湾区量子科学中心）；Institute of Quantum Information and Technology, Nanjing University of Posts and Telecommunications（南京邮电大学量子信息与信息技术研究所）；South China Normal University（华南师范大学）；Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials（广东省量子工程与量子材料重点实验室）；Guangdong-Hong Kong Joint Laboratory of Quantum Matter（粤港澳量子物质联合实验室）；Frontier Research Institute for Physics, South China Normal University（华南师范大学物理前沿研究院）
A Tunable, Modeless, and Hybridization-free Cross-Kerr Coupler for Miniaturized Superconducting Qubits
Kavli Nanoscience Institute and Thomas J. Watson, Sr., Laboratory of Applied Physics, California Institute of Technology（加州理工学院卡尔弗纳米科学研究所和托马斯·J·沃森Sr.应用物理实验室）；Institute for Quantum Information and Matter, California Institute of Technology（加州理工学院量子信息与物质研究所）
Extensible Fluxonium Architecture Using Tunable Couplers with Low Shunt Capacitance
Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area（粤港澳大湾区量子科学中心）；Institute of Quantum Information and Technology, Nanjing University of Posts and Telecommunications（南京邮电大学量子信息与科技研究院）；Jiangsu Key Laboratory of Quantum Information Science and Technology, Nanjing University（南京大学江苏省量子信息科学与技术重点实验室）；Key Laboratory of Atomic and Subatomic Structure and Quantum Control (South China Normal University), Ministry of Education（教育部原子与亚原子结构及量子控制重点实验室（华南师范大学））；School of Physics, South China Normal University（华南师范大学物理学院）；Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials（广东省量子工程与量子材料重点实验室）；Frontier Research Institute for Physics, South China Normal University（华南师范大学前沿物理研究所）
Fast CZ gate in hybrid fluxonium-transmon systems with tunable couplers
Nanjing University of Posts and Telecommunications（南京邮电大学）；Nanjing University（南京大学）；Shanxi University（山西大学）；Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area（粤港澳大湾区量子科学中心）
