Rapid and Unconditional Parametric Reset Protocol for Tunable Superconducting Qubits

  1. Yu Zhou,
  2. Zhenxing Zhang,
  3. Zelong Yin,
  4. Sainan Huai,
  5. Xiu Gu,
  6. Xiong Xu,
  7. Jonathan Allcock,
  8. Fuming Liu,
  9. Guanglei Xi,
  10. Qiaonian Yu,
  11. Hualiang Zhang,
  12. Mengyu Zhang,
  13. Hekang Li,
  14. Xiaohui Song,
  15. Zhan Wang,
  16. Dongning Zheng,
  17. Shuoming An,
  18. Yarui Zheng,
  19. and Shengyu Zhang
Qubit initialization is critical for many quantum algorithms and error correction schemes, and extensive efforts have been made to achieve this with high speed and efficiency. Here
we experimentally demonstrate a fast and high fidelity reset scheme for tunable superconducting qubits. A rapid decay channel is constructed by modulating the flux through a transmon qubit and realizing a swap between the qubit and its readout resonator. The residual excited population can be suppressed to 0.08% ± 0.08% within 34 ns, and the scheme requires no additional chip architecture, projective measurements, or feedback loops. In addition, the scheme has negligible effects on neighboring qubits, and is therefore suitable for large-scale multi-qubit systems. Our method also offers a way of entangling the qubit state with an itinerant single photon, particularly useful in quantum communication and quantum network applications.