A high⁃fidelity controlled⁃phase gate betweentwo superconducting qubits(Invited)

doi:10.3969/j.issn.1007-5461.2026.04.004

Abstract

Abstract: Superconducting circuits are particularly appealing as platforms for quantum computing due to the good scalability of their associated microfabrication techniques. Significant progress has been made in superconducting qubits, however, performing universal quantum gate operations between an arbitrary pair of distant qubits with fidelity above the fault-tolerant threshold remains a challenging goal in multi-qubit quantum processors, which is crucial for executing quantum algorithms. Here, we present a mechanism and its experimental demonstration for achieving this objective by adopting an architecture in which multiple frequency-tunable qubits are coupled with a resonator. A controlled-phase gate between any two qubits is realized through a coherent photon exchange process mediated by the resonator, and tailored by dynamically adjusting the coupling strength between one qubit and the resonator. Numerical simulations indicate that, according to the proposed mechanism, the gate fidelity exceeding the fault-tolerant threshold can be achieved within a considerable gate operation time. These characteristics render the approach highly suitable for implementing logical operations in large-scale superconducting quantum processors with all-to-all connectivity.

Key words: quantum computation, controlled-phase gate, quantum process tomography, superconducting quantum qubits

CLC Number:

O431.2

NING Wen , YANG Zhenbiao, ZHENG Shibiao . A high⁃fidelity controlled⁃phase gate betweentwo superconducting qubits(Invited)[J]. Chinese Journal of Quantum Electronics, 2026, 43(4): 539-548.

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