In situ mixer calibration for superconducting quantum circuits

  1. Nan Wu,
  2. Jing Lin,
  3. Changrong Xie,
  4. Zechen Guo,
  5. Wenhui Huang,
  6. Libo Zhang,
  7. Yuxuan Zhou,
  8. Xuandong Sun,
  9. Jiawei Zhang,
  10. Weijie Guo,
  11. Xiayu Linpeng,
  12. Song Liu,
  13. Yang Liu,
  14. Wenhui Ren,
  15. Ziyu Tao,
  16. Ji Jiang,
  17. Ji Chu,
  18. Jingjing Niu,
  19. Youpeng Zhong,
  20. and Dapeng Yu
Mixers play a crucial role in superconducting quantum computing, primarily by facilitating frequency conversion of signals to enable precise control and readout of quantum states. However,
imperfections, particularly carrier leakage and unwanted sideband signal, can significantly compromise control fidelity. To mitigate these defects, regular and precise mixer calibrations are indispensable, yet they pose a formidable challenge in large-scale quantum control. Here, we introduce an in situ calibration technique and outcome-focused mixer calibration scheme using superconducting qubits. Our method leverages the qubit’s response to imperfect signals, allowing for calibration without modifying the wiring configuration. We experimentally validate the efficacy of this technique by benchmarking single-qubit gate fidelity and qubit coherence time.