Driven dynamics and rotary echo of a qubit tunably coupled to a harmonic oscillator

Simon Gustavsson; Jonas Bylander; Fei Yan; Pol Forn-Díaz; Vlad Bolkhovsky; Danielle Braje; George Fitch; Khalil Harrabi; Donna Lennon; Jovi Miloshi; Peter Murphy; Rick Slattery; Steven Spector; Ben Turek; Terry Weir; Paul B. Welander; Fumiki Yoshihara; David G. Cory; Yasunobu Nakamura; Terry P. Orlando; William D. Oliver

doi:10.1103/physrevlett.108.170503

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arXiv · 1201.6341

Driven dynamics and rotary echo of a qubit tunably coupled to a harmonic oscillator

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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.

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Simon Gustavsson, Jonas Bylander, Fei Yan, Pol Forn-Díaz, Vlad Bolkhovsky, Danielle Braje, George Fitch, Khalil Harrabi, Donna Lennon, Jovi Miloshi, Peter Murphy, Rick Slattery, Steven Spector, Ben Turek, Terry Weir, Paul B. Welander, Fumiki Yoshihara, David G. Cory, Yasunobu Nakamura, Terry P. Orlando, William D. Oliver. 2012-01-30. Driven dynamics and rotary echo of a qubit tunably coupled to a harmonic oscillator. https://doi.org/10.1103/physrevlett.108.170503

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