Wuxin Liu

10-qubit entanglement and parallel logic operations with a superconducting circuit

  1. Chao Song,
  2. Kai Xu,
  3. Wuxin Liu,
  4. Chuiping Yang,
  5. Shi-Biao Zheng,
  6. Hui Deng,
  7. Qiwei Xie,
  8. Keqiang Huang,
  9. Qiujiang Guo,
  10. Libo Zhang,
  11. Pengfei Zhang,
  12. Da Xu,
  13. Dongning Zheng,
  14. Xiaobo Zhu,
  15. H. Wang,
  16. Y.-A. Chen,
  17. C.-Y. Lu,
  18. Siyuan Han,
  19. and J.-W. Pan
Here we report on the production and tomography of genuinely entangled Greenberger-Horne-Zeilinger states with up to 10 qubits connecting to a bus resonator in a superconducting circuit,
where the resonator-mediated qubit-qubit interactions are used to controllably entangle multiple qubits and to operate on different pairs of qubits in parallel. The resulting 10-qubit density matrix is unambiguously probed, with a fidelity of 0.668±0.025. Our results demonstrate the largest entanglement created so far in solid-state architectures, and pave the way to large-scale quantum computation.
arxiv pdf

Solving Systems of Linear Equations with a Superconducting Quantum Processor

  1. Yarui Zheng,
  2. Chao Song,
  3. Ming-Cheng Chen,
  4. Benxiang Xia,
  5. Wuxin Liu,
  6. Qiujiang Guo,
  7. Libo Zhang,
  8. Da Xu,
  9. Hui Deng,
  10. Keqiang Huang,
  11. Yulin Wu,
  12. Zhiguang Yan,
  13. Dongning Zheng,
  14. Li Lu,
  15. Jian-Wei Pan,
  16. H. Wang,
  17. Chao-Yang Lu,
  18. and Xiaobo Zhu
Superconducting quantum circuits are promising candidate for building scalable quantum computers. Here, we use a four-qubit superconducting quantum processor to solve a two-dimensional
system of linear equations based on a quantum algorithm proposed by Harrow, Hassidim, and Lloyd [Phys. Rev. Lett. \textbf{103}, 150502 (2009)], which promises an exponential speedup over classical algorithms under certain circumstances. We benchmark the solver with quantum inputs and outputs, and characterize it by non-trace-preserving quantum process tomography, which yields a process fidelity of 0.837±0.006. Our results highlight the potential of superconducting quantum circuits for applications in solving large-scale linear systems, a ubiquitous task in science and engineering.
arxiv pdf