Driven dynamics and rotary echo of a qubit tunably coupled to a harmonic oscillator.
/ Authors
S. Gustavsson, J. Bylander, F. Yan, P. Forn-Díaz, V. Bolkhovsky, D. Braje, G. Fitch, K. Harrabi, D. Lennon, J. Miloshi
and 11 more authors
P. Murphy, R. Slattery, S. Spector, B. Turek, T. Weir, P. Welander, F. Yoshihara, D. Cory, Y. Nakamura, T. Orlando, W. Oliver
/ Abstract
We have investigated the driven dynamics of a superconducting flux qubit that is tunably coupled to a microwave resonator. We find that the qubit experiences an oscillating field mediated by off-resonant driving of the resonator, leading to strong modifications of the qubit Rabi frequency. This opens an additional noise channel, and we find that low-frequency noise in the coupling parameter causes a reduction of the coherence time during driven evolution. The noise can be mitigated with the rotary-echo pulse sequence, which, for driven systems, is analogous to the Hahn-echo sequence.
Journal: Physical review letters