Superconducting qubits reset and read in under a resonator cycle

Researchers affiliated with Forschungszentrum Jülich, Aarhus University, and Chalmers University of Technology have demonstrated a dispersive measurement method for superconducting qubits that simultaneously measures a qubit's state and resets the readout resonator. This combined operation addresses a key bottleneck in quantum computing speed by eliminating the need for separate measurement and reset steps. The work demonstrates driving the resonator to approximately 10^2 photons and back to approximately 10^(-3) photons in less than three times the resonator's natural decay rate while maintaining an assignment error below 1% due to T_1 limitations. The approach utilizes analytically defined pulses and extends to measuring an arbitrary number of qubit states, including qutrits. This rapid cavity reset…