1
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Du B, Suresh R, López S, Cadiente J, Ma R. Probing Site-Resolved Current in Strongly Interacting Superconducting Circuit Lattices. PHYSICAL REVIEW LETTERS 2024; 133:060601. [PMID: 39178460 DOI: 10.1103/physrevlett.133.060601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Accepted: 07/08/2024] [Indexed: 08/25/2024]
Abstract
Transport measurements are fundamental for understanding condensed matter phenomena, from superconductivity to the fractional quantum Hall effect. Analogously, they can be powerful tools for probing synthetic quantum matter in quantum simulators. Here we demonstrate the measurement of in situ particle current in a superconducting circuit lattice and apply it to study transport in both coherent and bath-coupled lattices. Our method utilizes controlled tunneling in a double-well potential to map current to on-site density, revealing site-resolved current and current statistics. We prepare a strongly interacting Bose-Hubbard lattice at different lattice fillings, and observe the change in current statistics as the many-body states transition from superfluid to Mott insulator. Furthermore, we explore nonequilibrium current dynamics by coupling the lattice to engineered driven-dissipative baths that serve as tunable particle source and drain. We observe steady-state current in discrete conduction channels and interaction-assisted transport. These results establish a versatile platform to investigate microscopic quantum transport in superconducting circuits.
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2
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Gaikwad C, Kowsari D, Brame C, Song X, Zhang H, Esposito M, Ranadive A, Cappelli G, Roch N, Levenson-Falk EM, Murch KW. Entanglement Assisted Probe of the Non-Markovian to Markovian Transition in Open Quantum System Dynamics. PHYSICAL REVIEW LETTERS 2024; 132:200401. [PMID: 38829081 DOI: 10.1103/physrevlett.132.200401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 04/16/2024] [Indexed: 06/05/2024]
Abstract
We utilize a superconducting qubit processor to experimentally probe non-Markovian dynamics of an entangled qubit pair. We prepare an entangled state between two qubits and monitor the evolution of entanglement over time as one of the qubits interacts with a small quantum environment consisting of an auxiliary transmon qubit coupled to its readout cavity. We observe the collapse and revival of the entanglement as a signature of quantum memory effects in the environment. We then engineer the non-Markovianity of the environment by populating its readout cavity with thermal photons to show a transition from non-Markovian to Markovian dynamics, ultimately reaching a regime where the quantum Zeno effect creates a decoherence-free subspace that effectively stabilizes the entanglement between the qubits.
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Affiliation(s)
| | - Daria Kowsari
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
- Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, California 90089, USA
- Department of Physics & Astronomy, University of Southern California, Los Angeles, California 90089, USA
| | - Carson Brame
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - Xingrui Song
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - Haimeng Zhang
- Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, California 90089, USA
- Ming Hsieh Department of Electrical & Computer Engineering, University of Southern California, Los Angeles, California 90089, USA
| | - Martina Esposito
- CNR-SPIN Complesso di Monte S. Angelo, via Cintia, Napoli 80126, Italy
| | - Arpit Ranadive
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Giulio Cappelli
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Nicolas Roch
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Eli M Levenson-Falk
- Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, California 90089, USA
- Department of Physics & Astronomy, University of Southern California, Los Angeles, California 90089, USA
- Ming Hsieh Department of Electrical & Computer Engineering, University of Southern California, Los Angeles, California 90089, USA
| | - Kater W Murch
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
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3
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Ann BM, Deve S, Steele GA. Resolving Nonperturbative Renormalization of a Microwave-Dressed Weakly Anharmonic Superconducting Qubit Coupled to a Single Quantized Mode. PHYSICAL REVIEW LETTERS 2023; 131:193605. [PMID: 38000406 DOI: 10.1103/physrevlett.131.193605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/01/2023] [Accepted: 10/02/2023] [Indexed: 11/26/2023]
Abstract
Microwave driving is a ubiquitous technique for superconducting qubits, but the dressed states description based on the conventionally used perturbation theory cannot fully capture the dynamics in the strong driving limit. Comprehensive studies beyond these approximations applicable to transmon-based circuit quantum electrodynamics (QED) systems are unfortunately rare, as the relevant works have been mainly limited to single-mode or two-state systems. In this work, we investigate a microwave-dressed transmon coupled to a single quantized mode over a wide range of driving parameters. We reveal that the interaction between the transmon and resonator as well as the properties of each mode is significantly renormalized in the strong driving limit. Unlike previous theoretical works, we establish a nonrecursive and non-Floquet theory beyond the perturbative regimes, which excellently quantifies the experiments. This work expands our fundamental understanding of dressed cavity QED-like systems beyond the conventional approximations. Our work will also contribute to fast quantum gate implementation, qubit parameter engineering, and fundamental studies on driven nonlinear systems.
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Affiliation(s)
- Byoung-Moo Ann
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
- Quantum Technology Institute, Korea Research Institute of Standards and Science, 34113 Daejeon, South Korea
| | - Sercan Deve
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
| | - Gary A Steele
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
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4
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Chen S, Cotler J, Huang HY, Li J. The complexity of NISQ. Nat Commun 2023; 14:6001. [PMID: 37752125 PMCID: PMC10522708 DOI: 10.1038/s41467-023-41217-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 08/25/2023] [Indexed: 09/28/2023] Open
Abstract
The recent proliferation of NISQ devices has made it imperative to understand their power. In this work, we define and study the complexity class NISQ, which encapsulates problems that can be efficiently solved by a classical computer with access to noisy quantum circuits. We establish super-polynomial separations in the complexity among classical computation, NISQ, and fault-tolerant quantum computation to solve some problems based on modifications of Simon's problems. We then consider the power of NISQ for three well-studied problems. For unstructured search, we prove that NISQ cannot achieve a Grover-like quadratic speedup over classical computers. For the Bernstein-Vazirani problem, we show that NISQ only needs a number of queries logarithmic in what is required for classical computers. Finally, for a quantum state learning problem, we prove that NISQ is exponentially weaker than classical computers with access to noiseless constant-depth quantum circuits.
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Affiliation(s)
- Sitan Chen
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, USA.
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, USA.
| | - Jordan Cotler
- Society of Fellows, Harvard University, Cambridge, MA, USA.
| | - Hsin-Yuan Huang
- Institute for Quantum Information and Matter, CAltech, Pasadena, CA, USA.
- Department of Computing and Mathematical Sciences, CAltech, Pasadena, CA, USA.
| | - Jerry Li
- Microsoft Research AI, Redmond, WA, USA.
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5
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Shi YH, Liu Y, Zhang YR, Xiang Z, Huang K, Liu T, Wang YY, Zhang JC, Deng CL, Liang GH, Mei ZY, Li H, Li TM, Ma WG, Liu HT, Chen CT, Liu T, Tian Y, Song X, Zhao SP, Xu K, Zheng D, Nori F, Fan H. Quantum Simulation of Topological Zero Modes on a 41-Qubit Superconducting Processor. PHYSICAL REVIEW LETTERS 2023; 131:080401. [PMID: 37683167 DOI: 10.1103/physrevlett.131.080401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 06/29/2023] [Accepted: 07/25/2023] [Indexed: 09/10/2023]
Abstract
Quantum simulation of different exotic topological phases of quantum matter on a noisy intermediate-scale quantum (NISQ) processor is attracting growing interest. Here, we develop a one-dimensional 43-qubit superconducting quantum processor, named Chuang-tzu, to simulate and characterize emergent topological states. By engineering diagonal Aubry-André-Harper (AAH) models, we experimentally demonstrate the Hofstadter butterfly energy spectrum. Using Floquet engineering, we verify the existence of the topological zero modes in the commensurate off-diagonal AAH models, which have never been experimentally realized before. Remarkably, the qubit number over 40 in our quantum processor is large enough to capture the substantial topological features of a quantum system from its complex band structure, including Dirac points, the energy gap's closing, the difference between even and odd number of sites, and the distinction between edge and bulk states. Our results establish a versatile hybrid quantum simulation approach to exploring quantum topological systems in the NISQ era.
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Affiliation(s)
- Yun-Hao Shi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Yu Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu-Ran Zhang
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510640, China
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wako-shi, Saitama 351-0198, Japan
- Center for Quantum Computing, RIKEN, Wako-shi, Saitama 351-0198, Japan
| | - Zhongcheng Xiang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kaixuan Huang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Tao Liu
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510640, China
| | - Yong-Yi Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jia-Chi Zhang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cheng-Lin Deng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gui-Han Liang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng-Yang Mei
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Tian-Ming Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Guo Ma
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao-Tian Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chi-Tong Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tong Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ye Tian
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaohui Song
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - S P Zhao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Kai Xu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100049, China
| | - Dongning Zheng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100049, China
| | - Franco Nori
- Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, Wako-shi, Saitama 351-0198, Japan
- Center for Quantum Computing, RIKEN, Wako-shi, Saitama 351-0198, Japan
- Physics Department, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
| | - Heng Fan
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100049, China
- Hefei National Laboratory, Hefei 230088, China
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6
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Ban Y, Torrontegui E, Casanova J. Quantum neural networks with multi-qubit potentials. Sci Rep 2023; 13:9096. [PMID: 37277364 DOI: 10.1038/s41598-023-35867-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 05/25/2023] [Indexed: 06/07/2023] Open
Abstract
We propose quantum neural networks that include multi-qubit interactions in the neural potential leading to a reduction of the network depth without losing approximative power. We show that the presence of multi-qubit potentials in the quantum perceptrons enables more efficient information processing tasks such as XOR gate implementation and prime numbers search, while it also provides a depth reduction to construct distinct entangling quantum gates like CNOT, Toffoli, and Fredkin. This simplification in the network architecture paves the way to address the connectivity challenge to scale up a quantum neural network while facilitating its training.
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Affiliation(s)
- Yue Ban
- TECNALIA, Basque Research and Technology Alliance (BRTA), 48160, Derio, Spain.
| | - E Torrontegui
- Departamento de Física, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés (Madrid), Spain
- Instituto de Física Fundamental IFF-CSIC, Calle Serrano 113, 28006, Madrid, Spain
| | - J Casanova
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain
- EHU Quantum Center, University of the Basque Country UPV/EHU, Leioa, Spain
- Basque Foundation for Science, IKERBASQUE, Plaza Euskadi 5, 48009, Bilbao, Spain
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7
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Huang C, Wang T, Wu F, Ding D, Ye Q, Kong L, Zhang F, Ni X, Song Z, Shi Y, Zhao HH, Deng C, Chen J. Quantum Instruction Set Design for Performance. PHYSICAL REVIEW LETTERS 2023; 130:070601. [PMID: 36867808 DOI: 10.1103/physrevlett.130.070601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
A quantum instruction set is where quantum hardware and software meet. We develop characterization and compilation techniques for non-Clifford gates to accurately evaluate its designs. Applying these techniques to our fluxonium processor, we show that replacing the iSWAP gate by its square root SQiSW leads to a significant performance boost at almost no cost. More precisely, on SQiSW we measure a gate fidelity of up to 99.72% and averaging at 99.31%, and realize Haar random two-qubit gates with an average fidelity of 96.38%. This is an average error reduction of 41% for the former and a 50% reduction for the latter compared to using iSWAP on the same processor.
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Affiliation(s)
- Cupjin Huang
- Alibaba Quantum Laboratory, Alibaba Group USA, Bellevue, Washington 98004, USA
| | - Tenghui Wang
- Alibaba Quantum Laboratory, Alibaba Group, Hangzhou, Zhejiang 311121, People's Republic of China
| | - Feng Wu
- Alibaba Quantum Laboratory, Alibaba Group, Hangzhou, Zhejiang 311121, People's Republic of China
| | - Dawei Ding
- Alibaba Quantum Laboratory, Alibaba Group USA, Sunnyvale, California 94085, USA
| | - Qi Ye
- Alibaba Quantum Laboratory, Alibaba Group, Beijing 100102, People's Republic of China
- Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Linghang Kong
- Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Fang Zhang
- Alibaba Quantum Laboratory, Alibaba Group USA, Bellevue, Washington 98004, USA
| | - Xiaotong Ni
- Alibaba Quantum Laboratory, Alibaba Group, Hangzhou, Zhejiang 311121, People's Republic of China
| | - Zhijun Song
- Alibaba Quantum Laboratory, Alibaba Group, Hangzhou, Zhejiang 311121, People's Republic of China
| | - Yaoyun Shi
- Alibaba Quantum Laboratory, Alibaba Group USA, Bellevue, Washington 98004, USA
| | - Hui-Hai Zhao
- Alibaba Quantum Laboratory, Alibaba Group, Beijing 100102, People's Republic of China
| | - Chunqing Deng
- Alibaba Quantum Laboratory, Alibaba Group, Hangzhou, Zhejiang 311121, People's Republic of China
| | - Jianxin Chen
- Alibaba Quantum Laboratory, Alibaba Group USA, Bellevue, Washington 98004, USA
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8
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Menke T, Banner WP, Bergamaschi TR, Di Paolo A, Vepsäläinen A, Weber SJ, Winik R, Melville A, Niedzielski BM, Rosenberg D, Serniak K, Schwartz ME, Yoder JL, Aspuru-Guzik A, Gustavsson S, Grover JA, Hirjibehedin CF, Kerman AJ, Oliver WD. Demonstration of Tunable Three-Body Interactions between Superconducting Qubits. PHYSICAL REVIEW LETTERS 2022; 129:220501. [PMID: 36493437 DOI: 10.1103/physrevlett.129.220501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
Nonpairwise multiqubit interactions present a useful resource for quantum information processors. Their implementation would facilitate more efficient quantum simulations of molecules and combinatorial optimization problems, and they could simplify error suppression and error correction schemes. Here, we present a superconducting circuit architecture in which a coupling module mediates two-local and three-local interactions between three flux qubits by design. The system Hamiltonian is estimated via multiqubit pulse sequences that implement Ramsey-type interferometry between all neighboring excitation manifolds in the system. The three-local interaction is coherently tunable over several MHz via the coupler flux biases and can be turned off, which is important for applications in quantum annealing, analog quantum simulation, and gate-model quantum computation.
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Affiliation(s)
- Tim Menke
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - William P Banner
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Thomas R Bergamaschi
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Agustin Di Paolo
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Antti Vepsäläinen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Steven J Weber
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Roni Winik
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Alexander Melville
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Bethany M Niedzielski
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Danna Rosenberg
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Kyle Serniak
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Mollie E Schwartz
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Jonilyn L Yoder
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Alán Aspuru-Guzik
- Departments of Chemistry and Computer Science, University of Toronto, Toronto, Ontario M5G 1Z8, Canada
- Vector Institute for Artificial Intelligence, Toronto, Ontario M5S 1M1, Canada
- Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada
| | - Simon Gustavsson
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jeffrey A Grover
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Cyrus F Hirjibehedin
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - Andrew J Kerman
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
| | - William D Oliver
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02421-6426, USA
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9
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Zhao SK, Ge ZY, Xiang Z, Xue GM, Yan HS, Wang ZT, Wang Z, Xu HK, Su FF, Yang ZH, Zhang H, Zhang YR, Guo XY, Xu K, Tian Y, Yu HF, Zheng DN, Fan H, Zhao SP. Probing Operator Spreading via Floquet Engineering in a Superconducting Circuit. PHYSICAL REVIEW LETTERS 2022; 129:160602. [PMID: 36306769 DOI: 10.1103/physrevlett.129.160602] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/09/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Operator spreading, often characterized by out-of-time-order correlators (OTOCs), is one of the central concepts in quantum many-body physics. However, measuring OTOCs is experimentally challenging due to the requirement of reversing the time evolution of systems. Here we apply Floquet engineering to investigate operator spreading in a superconducting 10-qubit chain. Floquet engineering provides an effective way to tune the coupling strength between nearby qubits, which is used to demonstrate quantum walks with tunable couplings, reversed time evolution, and the measurement of OTOCs. A clear light-cone-like operator propagation is observed in the system with multiple excitations, and has a nearly equal velocity as the single-particle quantum walk. For the butterfly operator that is nonlocal (local) under the Jordan-Wigner transformation, the OTOCs show distinct behaviors with (without) a signature of information scrambling in the near integrable system.
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Affiliation(s)
- S K Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Zi-Yong Ge
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Zhongcheng Xiang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - G M Xue
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - H S Yan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Z T Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Zhan Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - H K Xu
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - F F Su
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Z H Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - He Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Ran Zhang
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
| | - Xue-Yi Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Kai Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100190, China
| | - Ye Tian
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - H F Yu
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - D N Zheng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Heng Fan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - S P Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan 523808, China
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10
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Yarkoni S, Raponi E, Bäck T, Schmitt S. Quantum annealing for industry applications: introduction and review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:104001. [PMID: 36001953 DOI: 10.1088/1361-6633/ac8c54] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Quantum annealing (QA) is a heuristic quantum optimization algorithm that can be used to solve combinatorial optimization problems. In recent years, advances in quantum technologies have enabled the development of small- and intermediate-scale quantum processors that implement the QA algorithm for programmable use. Specifically, QA processors produced by D-Wave systems have been studied and tested extensively in both research and industrial settings across different disciplines. In this paper we provide a literature review of the theoretical motivations for QA as a heuristic quantum optimization algorithm, the software and hardware that is required to use such quantum processors, and the state-of-the-art applications and proofs-of-concepts that have been demonstrated using them. The goal of our review is to provide a centralized and condensed source regarding applications of QA technology. We identify the advantages, limitations, and potential of QA for both researchers and practitioners from various fields.
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11
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Zhou Y, Zhang Z, Yin Z, Huai S, Gu X, Xu X, Allcock J, Liu F, Xi G, Yu Q, Zhang H, Zhang M, Li H, Song X, Wang Z, Zheng D, An S, Zheng Y, Zhang S. Rapid and unconditional parametric reset protocol for tunable superconducting qubits. Nat Commun 2021; 12:5924. [PMID: 34635663 PMCID: PMC8505451 DOI: 10.1038/s41467-021-26205-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/13/2021] [Indexed: 11/09/2022] Open
Abstract
Qubit initialization is a critical task in quantum computation and communication. Extensive efforts have been made to achieve this with high speed, efficiency and scalability. However, previous approaches have either been measurement-based and required fast feedback, suffered from crosstalk or required sophisticated calibration. Here, we report a fast and high-fidelity reset scheme, avoiding the issues above without any additional chip architecture. By modulating the flux through a transmon qubit, we realize a swap between the qubit and its readout resonator that suppresses the excited state population to 0.08% ± 0.08% within 34 ns (284 ns if photon depletion of the resonator is required). Furthermore, our approach (i) can achieve effective second excited state depletion, (ii) has negligible effects on neighboring qubits, and (iii) offers a way to entangle the qubit with an itinerant single photon, useful in quantum communication applications.
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Affiliation(s)
- Yu Zhou
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Zhenxing Zhang
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Zelong Yin
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Sainan Huai
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Xiu Gu
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Xiong Xu
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Jonathan Allcock
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Fuming Liu
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Guanglei Xi
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Qiaonian Yu
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Hualiang Zhang
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Mengyu Zhang
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Hekang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaohui Song
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhan Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dongning Zheng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuoming An
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China.
| | - Yarui Zheng
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
| | - Shengyu Zhang
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong, 518057, China
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12
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Winick A, Wallman JJ, Emerson J. Simulating and Mitigating Crosstalk. PHYSICAL REVIEW LETTERS 2021; 126:230502. [PMID: 34170151 DOI: 10.1103/physrevlett.126.230502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 05/04/2021] [Indexed: 06/13/2023]
Abstract
We describe an efficient and scalable framework for modeling crosstalk effects on quantum information processors. By applying optimal control techniques, we show how to tune-up arbitrary high-fidelity parallel operations on systems with substantial local and nonlocal crosstalk. As an example, we simulate a 2D square array of 100 superconducting transmon qubits. These results suggest that rather than striving to engineer away undesirable interactions during fabrication, we can largely mitigate such effects with software through careful characterization and control optimization.
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Affiliation(s)
- Adam Winick
- Quantum Benchmark Inc., 51 Breithaupt Street Suite 100, Kitchener, Ontario N2H 4C3, Canada
- Institute for Quantum Computing, University of Waterloo, 200 University Avenue West Waterloo, Ontario N2L 3G1, Canada
| | - Joel J Wallman
- Quantum Benchmark Inc., 51 Breithaupt Street Suite 100, Kitchener, Ontario N2H 4C3, Canada
- Institute for Quantum Computing, University of Waterloo, 200 University Avenue West Waterloo, Ontario N2L 3G1, Canada
| | - Joseph Emerson
- Quantum Benchmark Inc., 51 Breithaupt Street Suite 100, Kitchener, Ontario N2H 4C3, Canada
- Institute for Quantum Computing, University of Waterloo, 200 University Avenue West Waterloo, Ontario N2L 3G1, Canada
- Canadian Institute for Advanced Research, MaRS Centre, West Tower 661 University Ave., Suite 505 Toronto, Ontario M5G 1M1, Canada
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13
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Malz D, Smith A. Topological Two-Dimensional Floquet Lattice on a Single Superconducting Qubit. PHYSICAL REVIEW LETTERS 2021; 126:163602. [PMID: 33961450 DOI: 10.1103/physrevlett.126.163602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/01/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Current noisy intermediate-scale quantum (NISQ) devices constitute powerful platforms for analog quantum simulation. The exquisite level of control offered by state-of-the-art quantum computers make them especially promising to implement time-dependent Hamiltonians. We implement quasiperiodic driving of a single qubit in the IBM Quantum Experience and thus experimentally realize a temporal version of the half-Bernevig-Hughes-Zhang Chern insulator. Using simple error mitigation, we achieve consistently high fidelities of around 97%. From our data we can infer the presence of a topological transition, thus realizing an earlier proposal of topological frequency conversion by Martin, Refael, and Halperin. Motivated by these results, we theoretically study the many-qubit case, and show that one can implement a wide class of Floquet Hamiltonians, or time-dependent Hamiltonians in general. Our study highlights promises and limitations when studying many-body systems through multifrequency driving of quantum computers.
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Affiliation(s)
- Daniel Malz
- Max Planck Institute for Quantum Optics, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany
- Munich Center for Quantum Science and Technology, Schellingstraße 4, D-80799 München, Germany
| | - Adam Smith
- Department of Physics, TFK, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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14
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Collodo MC, Herrmann J, Lacroix N, Andersen CK, Remm A, Lazar S, Besse JC, Walter T, Wallraff A, Eichler C. Implementation of Conditional Phase Gates Based on Tunable ZZ Interactions. PHYSICAL REVIEW LETTERS 2020; 125:240502. [PMID: 33412023 DOI: 10.1103/physrevlett.125.240502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/12/2020] [Indexed: 06/12/2023]
Abstract
High fidelity two-qubit gates exhibiting low cross talk are essential building blocks for gate-based quantum information processing. In superconducting circuits, two-qubit gates are typically based either on rf-controlled interactions or on the in situ tunability of qubit frequencies. Here, we present an alternative approach using a tunable cross-Kerr-type ZZ interaction between two qubits, which we realize with a flux-tunable coupler element. We control the ZZ-coupling rate over 3 orders of magnitude to perform a rapid (38 ns), high-contrast, low leakage (0.14±0.24%) conditional phase CZ gate with a fidelity of 97.9±0.7% as measured in interleaved randomized benchmarking without relying on the resonant interaction with a noncomputational state. Furthermore, by exploiting the direct nature of the ZZ coupling, we easily access the entire conditional phase gate family by adjusting only a single control parameter.
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Affiliation(s)
| | | | - Nathan Lacroix
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | | | - Ants Remm
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Stefania Lazar
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | | | - Theo Walter
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Andreas Wallraff
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
- Quantum Center, ETH Zurich, CH-8093 Zurich, Switzerland
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15
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Zhao P, Xu P, Lan D, Chu J, Tan X, Yu H, Yu Y. High-Contrast ZZ Interaction Using Superconducting Qubits with Opposite-Sign Anharmonicity. PHYSICAL REVIEW LETTERS 2020; 125:200503. [PMID: 33258656 DOI: 10.1103/physrevlett.125.200503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 08/11/2020] [Indexed: 06/12/2023]
Abstract
For building a scalable quantum processor with superconducting qubits, ZZ interaction is of great concern because its residual has a crucial impact to two-qubit gate fidelity. Two-qubit gates with fidelity meeting the criterion of fault-tolerant quantum computation have been demonstrated using ZZ interaction. However, as the performance of quantum processors improves, the residual static ZZ can become a performance-limiting factor for quantum gate operation and quantum error correction. Here, we introduce a superconducting architecture using qubits with opposite-sign anharmonicity, a transmon qubit, and a C-shunt flux qubit, to address this issue. We theoretically demonstrate that by coupling the two types of qubits, the high-contrast ZZ interaction can be realized. Thus, we can control the interaction with a high on-off ratio to implement two-qubit controlled-Z gates, or suppress it during two-qubit gate operation using XY interaction (e.g., an iSWAP gate). The proposed architecture can also be scaled up to multiqubit cases. In a fixed coupled system, ZZ crosstalk related to neighboring spectator qubits could also be heavily suppressed.
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Affiliation(s)
- Peng Zhao
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 230039, China
| | - Peng Xu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 230039, China
- Institute of Quantum Information and Technology, Nanjing University of Posts and Telecommunications, Nanjing 210003, China
- State Key Laboratory of Quantum Optics and Devices, Shanxi University, Taiyuan 030006, China
| | - Dong Lan
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 230039, China
| | - Ji Chu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 230039, China
| | - Xinsheng Tan
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 230039, China
| | - Haifeng Yu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 230039, China
| | - Yang Yu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 230039, China
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16
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Wu X, Tomarken SL, Petersson NA, Martinez LA, Rosen YJ, DuBois JL. High-Fidelity Software-Defined Quantum Logic on a Superconducting Qudit. PHYSICAL REVIEW LETTERS 2020; 125:170502. [PMID: 33156670 DOI: 10.1103/physrevlett.125.170502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
We present an efficient approach to achieving arbitrary, high-fidelity control of a multilevel quantum system using optimal control techniques. As an demonstration, we implement a continuous, software-defined microwave pulse to realize a 0↔2 SWAP gate that achieves an average gate fidelity of 99.4%. We describe our procedure for extracting the system Hamiltonian, calibrating the quantum and classical hardware chain, and evaluating the gate fidelity. Our work represents an alternative, fully generalizable route towards achieving universal quantum control by leveraging optimal control techniques.
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Affiliation(s)
- Xian Wu
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S L Tomarken
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Anders Petersson
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - L A Martinez
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Yaniv J Rosen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Jonathan L DuBois
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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17
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Xu Y, Hua Z, Chen T, Pan X, Li X, Han J, Cai W, Ma Y, Wang H, Song YP, Xue ZY, Sun L. Experimental Implementation of Universal Nonadiabatic Geometric Quantum Gates in a Superconducting Circuit. PHYSICAL REVIEW LETTERS 2020; 124:230503. [PMID: 32603172 DOI: 10.1103/physrevlett.124.230503] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
Using geometric phases to realize noise-resilient quantum computing is an important method to enhance the control fidelity. In this work, we experimentally realize a universal nonadiabatic geometric quantum gate set in a superconducting qubit chain. We characterize the realized single- and two-qubit geometric gates with both quantum process tomography and randomized benchmarking methods. The measured average fidelities for the single-qubit rotation gates and two-qubit controlled-Z gate are 0.9977(1) and 0.977(9), respectively. Besides, we also experimentally demonstrate the noise-resilient feature of the realized single-qubit geometric gates by comparing their performance with the conventional dynamical gates with different types of errors in the control field. Thus, our experiment proves a way to achieve high-fidelity geometric quantum gates for robust quantum computation.
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Affiliation(s)
- Y Xu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Z Hua
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Tao Chen
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - X Pan
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - X Li
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - J Han
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - W Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y Ma
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - H Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y P Song
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Zheng-Yuan Xue
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - L Sun
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
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18
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Han JX, Wu JL, Wang Y, Jiang YY, Xia Y, Song J. Multi-qubit phase gate on multiple resonators mediated by a superconducting bus. OPTICS EXPRESS 2020; 28:1954-1969. [PMID: 32121896 DOI: 10.1364/oe.384352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
We propose a one-step scheme for implementing multi-qubit phase gates on microwave photons in multiple resonators mediated by a superconducting bus in circuit quantum electrodynamics (QED) system. In the scheme, multiple single-mode resonators carry quantum information with their vacuum and single-photon Fock states, and a multi-level artificial atom acts as a quantum bus which induces the indirect interaction among resonators. The method of pulse engineering is used to shape the coupling strength between resonators and the bus so as to improve the fidelity and robustness of the scheme. We also discuss the influence of finite coherence time for the bus and resonators on gate fidelity respectively. Finally, we consider the suppression of unwanted transitions and propose the method of optimized detuning compensation for offsetting unwanted transitions, showing the feasibility of the scheme within the current experiment technology.
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19
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Continuous Variables Graph States Shaped as Complex Networks: Optimization and Manipulation. ENTROPY 2019; 22:e22010026. [PMID: 33285801 PMCID: PMC7516447 DOI: 10.3390/e22010026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 11/30/2022]
Abstract
Complex networks structures have been extensively used for describing complex natural and technological systems, like the Internet or social networks. More recently, complex network theory has been applied to quantum systems, where complex network topologies may emerge in multiparty quantum states and quantum algorithms have been studied in complex graph structures. In this work, we study multimode Continuous Variables entangled states, named cluster states, where the entanglement structure is arranged in typical real-world complex networks shapes. Cluster states are a resource for measurement-based quantum information protocols, where the quality of a cluster is assessed in terms of the minimal amount of noise it introduces in the computation. We study optimal graph states that can be obtained with experimentally realistic quantum resources, when optimized via analytical procedure. We show that denser and regular graphs allow for better optimization. In the spirit of quantum routing, we also show the reshaping of entanglement connections in small networks via linear optics operations based on numerical optimization.
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20
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Realization of efficient quantum gates with a superconducting qubit-qutrit circuit. Sci Rep 2019; 9:13389. [PMID: 31527726 PMCID: PMC6746868 DOI: 10.1038/s41598-019-49657-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 08/08/2019] [Indexed: 11/25/2022] Open
Abstract
Building a quantum computer is a daunting challenge since it requires good control but also good isolation from the environment to minimize decoherence. It is therefore important to realize quantum gates efficiently, using as few operations as possible, to reduce the amount of required control and operation time and thus improve the quantum state coherence. Here we propose a superconducting circuit for implementing a tunable system consisting of a qutrit coupled to two qubits. This system can efficiently accomplish various quantum information tasks, including generation of entanglement of the two qubits and conditional three-qubit quantum gates, such as the Toffoli and Fredkin gates. Furthermore, the system realizes a conditional geometric gate which may be used for holonomic (non-adiabatic) quantum computing. The efficiency, robustness and universality of the presented circuit makes it a promising candidate to serve as a building block for larger networks capable of performing involved quantum computational tasks.
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21
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Cai W, Han J, Mei F, Xu Y, Ma Y, Li X, Wang H, Song YP, Xue ZY, Yin ZQ, Jia S, Sun L. Observation of Topological Magnon Insulator States in a Superconducting Circuit. PHYSICAL REVIEW LETTERS 2019; 123:080501. [PMID: 31491216 DOI: 10.1103/physrevlett.123.080501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Indexed: 06/10/2023]
Abstract
Searching topological states in artificial systems has recently become a rapidly growing field of research. Meanwhile, significant experimental progress on observing topological phenomena has been made in superconducting circuits. However, topological insulator states have not yet been reported in this system. Here, for the first time, we experimentally realize a tunable dimerized spin chain model and observe the topological magnon insulator states in a superconducting qubit chain. Via parametric modulations of the qubit frequencies, we show that the qubit chain can be flexibly tuned into topologically trivial or nontrivial magnon insulator states. Based on monitoring the quantum dynamics of a single-qubit excitation in the chain, we not only measure the topological winding numbers, but also observe the topological magnon edge and defect states. Our experiment exhibits the great potential of tunable superconducting qubit chain as a versatile platform for exploring noninteracting and interacting symmetry-protected topological states.
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Affiliation(s)
- W Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - J Han
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Feng Mei
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan, Shanxi 030006, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Y Xu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y Ma
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - X Li
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - H Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Y P Song
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Zheng-Yuan Xue
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Zhang-Qi Yin
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Suotang Jia
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan, Shanxi 030006, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Luyan Sun
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
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22
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Ikonen J, Goetz J, Ilves J, Keränen A, Gunyho AM, Partanen M, Tan KY, Hazra D, Grönberg L, Vesterinen V, Simbierowicz S, Hassel J, Möttönen M. Qubit Measurement by Multichannel Driving. PHYSICAL REVIEW LETTERS 2019; 122:080503. [PMID: 30932559 DOI: 10.1103/physrevlett.122.080503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/13/2018] [Indexed: 06/09/2023]
Abstract
We theoretically propose and experimentally implement a method of measuring a qubit by driving it close to the frequency of a dispersively coupled bosonic mode. The separation of the bosonic states corresponding to different qubit states begins essentially immediately at maximum rate, leading to a speedup in the measurement protocol. Also the bosonic mode can be simultaneously driven to optimize measurement speed and fidelity. We experimentally test this measurement protocol using a superconducting qubit coupled to a resonator mode. For a certain measurement time, we observe that the conventional dispersive readout yields close to 100% higher average measurement error than our protocol. Finally, we use an additional resonator drive to leave the resonator state to vacuum if the qubit is in the ground state during the measurement protocol. This suggests that the proposed measurement technique may become useful in unconditionally resetting the resonator to a vacuum state after the measurement pulse.
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Affiliation(s)
- Joni Ikonen
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Jan Goetz
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Jesper Ilves
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Aarne Keränen
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Andras M Gunyho
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Matti Partanen
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Kuan Y Tan
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Dibyendu Hazra
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Leif Grönberg
- VTT Technical Research Centre of Finland, QTF Center of Excellence, P.O. Box 1000, FI-02044 VTT, Finland
| | - Visa Vesterinen
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
- VTT Technical Research Centre of Finland, QTF Center of Excellence, P.O. Box 1000, FI-02044 VTT, Finland
| | - Slawomir Simbierowicz
- VTT Technical Research Centre of Finland, QTF Center of Excellence, P.O. Box 1000, FI-02044 VTT, Finland
| | - Juha Hassel
- VTT Technical Research Centre of Finland, QTF Center of Excellence, P.O. Box 1000, FI-02044 VTT, Finland
| | - Mikko Möttönen
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
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