Fast Reset Protocol for Superconducting Transmon Qubits

For larger-scale quantum information processing, qubit reset plays an important role, as the coherent times for qubits are limited. However, previous schemes require either long reset times or a complex pulse calibration technique, leading to low efficiency in qubit reset. Here, we propose a fast and simple reset protocol for superconducting transmon qubits based on the coupler-coupled qubits architecture. In this setup, a mixing pulse is used to transfer the qubit excitation to the combined excitation of a low-qulity coupler and readout resonator, which will quickly decay to their respectively ground states, leading to efficient qubit reset to the ground state. Our numerical results show that the residual population of the qubit's excited state can be suppressed to 0.04% within 28 ns; the reset time will be 283 ns if photon depletion of the readout resonator is required. Thus, our protocol provides a promising way for the high-efficiency superconducting qubit reset.

Automated summary

For larger-scale quantum information processing, the efficient reset of qubits is crucial but has been a challenge. In this study, we propose a fast and simple reset protocol based on the coupler-coupled qubits architecture, which transfers the qubit excitation to the combined excitation of a low-quality coupler and readout resonator, leading to efficient qubit reset. Numerical results demonstrate that the protocol can suppress the residual population of the qubit's excited state to 0.04% within 28 ns.