Scalable Coherent Manipulation of Qubit Quantum States

Strategic Insights -

Researchers at the University of Science and Technology China have published a new report on scalable coherent manipulation of qubit quantum states, a crucial step towards building large-scale superconducting quantum processors for fault-tolerant quantum computing. The investigation proposes a scalable scheme to provide magnetic flux for qubits using an on-chip direct current source (OCDCS), demonstrating both theoretically and experimentally that only a single pulse is needed to deterministically modulate the magnetic flux. This breakthrough paves the way for scalable flux bias in large-scale superconducting quantum processors.

Key Takeaways:

  • The research proposes a scalable scheme to provide magnetic flux for qubits using an on-chip direct current source (OCDCS), demonstrating both theoretically and experimentally that only a single pulse is needed to deterministically modulate the magnetic flux.
  • The experimental results exhibit high-fidelity single-qubit gate and low noise current of the OCDCS, showing a 15.6 dB reduction compared with the RTE scheme.
  • The proposed time-division-multiplex (TDM) scheme combining the OCDCS with switch arrays could exponentially reduce the number of cables for flux bias from traditional n to log2(n) + 1, enabling scalability in large-scale superconducting quantum processors.
  • The research was funded by the Innovation Program for Quantum Science and Technology, Shanghai Municipal Science and Technology Major Project, Anhui Initiative in Quantum Information Technologies, and other institutions.
  • The study demonstrates the feasibility of scalable coherent manipulation of qubit quantum states, a crucial step towards building large-scale superconducting quantum processors for fault-tolerant quantum computing.

Statistics:

  • 15.6 dB reduction in noise current of the OCDCS compared with the RTE scheme.
  • log2(n) + 1 reduction in the number of cables for flux bias using the proposed TDM scheme.
  • 2025: the year in which the research was published.
  • 24(3): the volume and issue number of the Physical Review Applied journal where the research was published.
  • 230026: the postal code of the University of Science and Technology China's location in Hefei, People's Republic of China.

Sources:

  • On-chip Direct-current Source for Scalable Superconducting Quantum Computing. Physical Review Applied, 2025;24(3).
  • NewsRx. New Findings from University of Science and Technology China Update Understanding of Technology (On-chip Direct-current Source for Scalable Superconducting Quantum Computing). Journal of Engineering. October 20, 2025; p 1896.
  • Xiaobo Zhu, University of Science and Technology China, Hefei Natl Res Ctr Phys Sci Microscale, Hefei 230026, People's Republic of China.