Mitigating transients in flux-control signals in a superconducting quantum processor

  1. Anuj Aggarwal,
  2. Jorge Fernández-Pendás,
  3. Tahereh Abad,
  4. Daryoush Shiri,
  5. Halldór Jakobsson,
  6. Marcus Rommel,
  7. Andreas Nylander,
  8. Emil Hogedal,
  9. Amr Osman,
  10. Janka Biznárová,
  11. Robert Rehammar,
  12. Michele Faucci Giannelli,
  13. Anita Fadavi Roudsari,
  14. Jonas Bylander,
  15. and Giovanna Tancredi
Flux-tunable qubits and couplers are common components in superconducting quantum processors. However, dynamically controlling these elements via current pulses poses challenges due
to distortions and transients in the propagating signals. In particular, long-time transients can persist, adversely affecting subsequent qubit control operations. We model the flux control line as a first-order RC circuit and introduce a class of pulses designed to mitigate long-time transients. We theoretically demonstrate the robustness of these pulses against parameter mischaracterization and provide experimental evidence of their effectiveness in mitigating transients when applied to a flux-tunable qubit coupler. The proposed pulse design offers a practical solution for mitigating long-time transients, enabling efficient and reliable experiment tune-ups without requiring detailed flux line characterization.