Abhinav Kandala, Antonio Mezzacapo, et al.
Nature
We study bifurcation measurement of a multilevel superconducting qubit using a nonlinear resonator biased in the straddling regime, where the resonator frequency sits between two qubit transition frequencies. We find that high-fidelity bifurcation measurements are possible because of the enhanced qubit-state-dependent pull of the resonator frequency, the behavior of qubit-induced nonlinearities, and the reduced Purcell decay rate of the qubit that can be realized in this regime. Numerical simulations find up to a threefold improvement in qubit readout fidelity when operating in, rather than outside of, the straddling regime. High-fidelity measurements can be obtained at much smaller qubit-resonator couplings than current typical experimental realizations, reducing spectral crowding and potentially simplifying the implementation of multiqubit devices. © 2012 American Physical Society.
Abhinav Kandala, Antonio Mezzacapo, et al.
Nature
Martin Suchara, Andrew W. Cross, et al.
ISIT 2015
Martin Suchara, Andrew W. Cross, et al.
Quantum Information and Computation
F. Motzoi, Jay M. Gambetta, et al.
Physical Review A - AMO