Universal logical operations in a silicon quantum processor

ORAL

Abstract

Unavoidable errors induced by environmental noise preclude the direct implementation of practical quantum computation. Fault-tolerant quantum computation (FTQC) [1, 2] offers the only viable path forward, necessitating the encoding and processing of information within logical qubits to curb these unavoidable errors [3–7]. Although significant milestones have been achieved recently in the pursuit of building silicon quantum computers [8, 9], up to date, logical operations still haven't been realized in silicon.



In this presentation, we demonstrate a logical quantum processor using a phosphorus donor cluster in silicon. By implementing the [[4, 2, 2]] code [10–12], we realize the essential components for logical operations, which include fault-tolerant preparation of logical states and the characterization of a universal gate set comprising logical single- and two-qubit gates. In particular, the logical T gate is achieved using the gate-by-measurement method, based on which magic states are prepared. Furthermore, we execute the variational quantum eigensolver algorithm using two logical qubits to simulate the ground state of the electronic structure of the water molecule H2O. This work represents the key step towards scalable, fault-tolerant quantum computation in silicon spin qubits.

*This work was supported by the National Natural Science Foundation of China (Grants No. 92165210, 62174076, 11904157, 12275117, 12361161602), the Innovation Program for Quantum Science and Technology (No. 2021ZD0302300), Shenzhen Science, and Technology Program (Grants No. KQTD20200820113010023), Guangdong Basic and Applied Basic Research Foundation (2022B1515020074).

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Presenters

  • Chunhui Zhang

    • International Quantum Academy

Authors

  • Chunhui Zhang

    • International Quantum Academy

  • Feng Xu

    • International Quantum Academy

  • Shihang Zhang

    • International Quantum Academy

  • Mingchao Duan

    • International Quantum Academy

  • Guangchong Hu

    • International Quantum Academy

  • Tianluo Pan

    • International Quantum Academy

  • Peihao Huang

    • International Quantum Academy

  • Yu He

    • International Quantum Academy

  • Dapeng Yu

    • Shenzhen International Quantum Academy
    • International Quantum Academy
    • International Quantum Academy, Hefei National Laboratory-Shenzhen Branch