Dispersive Qubit Readout with Intrinsic Resonator Reset

Measurement and readout speed impose limits for logical qubit and qudit performance in quantum computing. Here, we experimentally demonstrate a universal analytical method for designing bandwidth-efficient dispersive readout pulses that intrinsically reset the resonator and extend it to multiple quantum states. The approach is based on universal analytical pulses and requires knowledge of the qubit and resonator parameters, but needs no direct optimization of the pulse shape, even when accounting for the nonlinearity of the system. When correcting for the Kerr nonlinearity, we find even more precise solutions to the speed-versus-photon-number trade-off, achieving 10 2 photon readout with reset to 10 − 2 within 3 κ − 1 duration and amplifier efficiency- and T 1 -limited assignment error around 0.6%. Results on qubits and qutrits validate the approach.