Genuine 12-Qubit Entanglement on a Superconducting Quantum Processor

Ming Gong; Ming-Cheng Chen; Yarui Zheng; Shiyu Wang; Chen Zha; Hui Deng; Zhiguang Yan; Hao Rong; Yulin Wu; Shaowei Li; Fusheng Chen; Youwei Zhao; Futian Liang; Jin Lin; Yu Xu; Cheng Guo; Lihua Sun; Anthony D Castellano; Haohua Wang; Chengzhi Peng; Chao-Yang Lu; Xiaobo Zhu; Jian-Wei Pan

doi:10.1103/PhysRevLett.122.110501

Genuine 12-Qubit Entanglement on a Superconducting Quantum Processor

Phys Rev Lett. 2019 Mar 22;122(11):110501. doi: 10.1103/PhysRevLett.122.110501.

Authors

Ming Gong^{1

2}, Ming-Cheng Chen^{1

2}, Yarui Zheng^{1

2}, Shiyu Wang^{1

2}, Chen Zha^{1

2}, Hui Deng^{1

2}, Zhiguang Yan^{1

2}, Hao Rong^{1

2}, Yulin Wu^{1

2}, Shaowei Li^{1

2}, Fusheng Chen^{1

2}, Youwei Zhao^{1

2}, Futian Liang^{1

2}, Jin Lin^{1

2}, Yu Xu^{1

2}, Cheng Guo^{1

2}, Lihua Sun^{1

2}, Anthony D Castellano^{1

2}, Haohua Wang³, Chengzhi Peng^{1

2}, Chao-Yang Lu^{1

2}, Xiaobo Zhu^{1

2}, Jian-Wei Pan^{1

2}

Affiliations

¹ Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
² Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China.
³ Department of Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China.

PMID: 30951346
DOI: 10.1103/PhysRevLett.122.110501

Abstract

We report the preparation and verification of a genuine 12-qubit entanglement in a superconducting processor. The processor that we designed and fabricated has qubits lying on a 1D chain with relaxation times ranging from 29.6 to 54.6 μs. The fidelity of the 12-qubit entanglement was measured to be above 0.5544±0.0025, exceeding the genuine multipartite entanglement threshold by 21 statistical standard deviations. After thermal cycling, the 12-qubit state fidelity was further improved to be above 0.707±0.008. Our entangling circuit to generate linear cluster states is depth invariant in the number of qubits and uses single- and double-qubit gates instead of collective interactions. Our results are a substantial step towards large-scale random circuit sampling and scalable measurement-based quantum computing.