Entanglement Detection and Characterization of Topological States

2021 Fiscal Year Annual Research Report

• Project/Area Number: 19F19326
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: NORI FRANCO 国立研究開発法人理化学研究所, 開拓研究本部, 主任研究員 (50415262)
• Co-Investigator(Kenkyū-buntansha): ZHANG YU-RAN 国立研究開発法人理化学研究所, .開拓研究本部, 外国人特別研究員
• Project Period (FY): 2019-11-08 – 2022-03-31
• Keywords: multipartite / entanglement / quantum simulation / superconducting qubits

Outline of Annual Research Achievements

We studied several emergent phenomena in quantum many-body systems from the perspective of quantum information. We theoretically studied topological phases in perturbed toric codes using quantum Fisher information (QFI). We showed thermalization and disorder-assisted stabilization of topological order after a quantum quench. We studied the 2D toric code at finite temperatures and showed that topological order cannot survive. Using a 19-qubit superconducting (SC) circuit, we generated and characterized multi-qubit entangled states. With 10 qubits, we measured the nonlinear squeezing parameter that had never been measured before. With all 19 qubits, we observed a metrological gain of 9.89 dB over the standard quantum limit, indicating a high level of entanglement for quantum-enhanced estimation sensitivity. We employed a 1D 12-qubit SC circuit to identify regimes of strong and weak thermalization with different states. Using a ladder-type SC circuit, we simulated both the XX-ladder and XX-chain models. We signaled thermalization and information scrambling in the XX ladder, which are absent in the XX chain. We realized a deterministic one-way C-not gate and one-way X rotations on IBM’s quantum-computing platform. We used multipartite entanglement to detect dynamical phase transitions using 16 SC qubits. We demonstrated the engineering of multiple dissipative channels by controlling adjacent nuclear spins of a NV center and observed the QFI’s flows to and from the environment.

Research Progress Status

令和3年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和3年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Multipartite entanglement of the topologically ordered state in a perturbed toric code (2022)
  • Author(s): Yu-Ran Zhang, Yu Zeng, Tao Liu, Heng Fan, J. Q. You, Franco Nori
  • Journal Title: Physical Review Research (2022) Volume: 03315 V1 Pages: 1-10
  • DOI: 10.48550/arXiv.2109.03315
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Observation of thermalization and information scrambling in a superconducting quantum processor (2022)
  • Author(s): Qingling Zhu, Zheng-Hang Sun, Ming Gong, Fusheng Chen, Yu-Ran Zhang, Yulin Wu, Yangsen Ye, Chen Zha, Shaowei Li, Shaojun Guo, Haoran Qian, He-Liang Huang, Jiale Yu, Hui Deng, Hao Rong, Jin Lin, Yu Xu, Lihua Sun, Cheng Guo, Na Li, Futian Liang, Cheng-Zhi Peng, Heng Fan, Xiaobo Zhu, and Jian-Wei Pan
  • Journal Title: Physical Review Letters Volume: 128 Pages: 1-6
  • DOI: 10.1103/PhysRevLett.128.160502
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Metrological characterization of non-Gaussian entangled states of superconducting qubits (2022)
  • Author(s): Kai Xu, Yu-Ran Zhang, Zheng-Hang Sun, Hekang Li, Pengtao Song, Zhongcheng Xiang, Kaixuan Huang, Hao Li, Yun-Hao Shi, Chi-Tong Chen, Xiaohui Song, Dongning Zheng, Franco Nori, H. Wang, Heng Fan
  • Journal Title: Physical Review Letters Volume: 128 Pages: 1-8
  • DOI: 10.1103/PhysRevLett.128.150501
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Deterministic one-way logic gates on a cloud quantum computer (2022)
  • Author(s): Zhi-Peng Yang, Alakesh Baishya, Huan-Yu Ku, Yu-Ran Zhang, Anton Frisk Kockum, Yueh-Nan Chen, Fu-Li Li, Jaw-Shen Tsai, Franco Nori
  • Journal Title: Physical Review A Volume: 105 Pages: 1-12
  • DOI: 10.1103/PhysRevA.105.042610
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Discrete time crystal in a driven-dissipative Bose-Hubbard model with two-photon processes (2022)
  • Author(s): Tong Liu, Yu-Ran Zhang, Kai Xu, Jian Cui, and Heng Fan
  • Journal Title: Physical Review A Volume: 105, 013710 Pages: 1-10
  • DOI: 10.1103/PhysRevA.105.013710
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Observation of Strong and Weak Thermalization in a Superconducting Quantum Processor (2021)
  • Author(s): Fusheng Chen, Zheng-Hang Sun, Ming Gong, Qingling Zhu, Yu-Ran Zhang, Yulin Wu, Yangsen Ye, Chen Zha, Shaowei Li, Shaojun Guo, Haoran Qian, He-Liang Huang, Jiale Yu, Hui Deng, Hao Rong, Jin Lin, Yu Xu, Lihua Sun, Cheng Guo, Na Li, Futian Liang, Cheng-Zhi Peng, Heng Fan, Xiaobo Zhu, and Jian-Wei Pan
  • Journal Title: Physical Review Letters Volume: 127 Pages: 1-6
  • DOI: 10.1103/PhysRevLett.127.020602
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Observation of Bloch oscillations and Wannier-Stark localization on a superconducting processor (2021)
  • Author(s): Xue-Yi Guo, Zi-Yong Ge, Hekang Li, Zhan Wang, Yu-Ran Zhang, Peangtao Song, Zhongcheng Xiang, Xiaohui Song, Yirong Jin, Kai Xu, Dongning Zheng, and Heng Fan
  • Journal Title: npj Quantum Information Volume: 7, Article number: 51 Pages: 1-6
  • DOI: 10.1038/s41534-021-00385-3
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Observing nonlinear spin squeezing and entanglement of non-Gaussian states with interconnected superconducting qubits (2021)
  • Author(s): Yu-Ran Zhang
  • Organizer: APS March Meeting 2021
  • Int'l Joint Research