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arXiv · 1010.6248

Circuit QED with a Nonlinear Resonator : ac-Stark Shift and Dephasing

F. R. Ong·M. Boissonneault·F. Mallet·A. Palacios-Laloy·A. Dewes·A. C. Doherty·A. Blais·P. Bertet·D. Vion·D. Esteve
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Abstract

We have performed spectroscopic measurements of a superconducting qubit dispersively coupled to a nonlinear resonator driven by a pump microwave field. Measurements of the qubit frequency shift provide a sensitive probe of the intracavity field, yielding a precise characterization of the resonator nonlinearity. The qubit linewidth has a complex dependence on the pump frequency and amplitude, which is correlated with the gain of the nonlinear resonator operated as a small-signal amplifier. The corresponding dephasing rate is found to be close to the quantum limit in the low-gain limit of the amplifier.

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F. R. Ong, M. Boissonneault, F. Mallet, A. Palacios-Laloy, A. Dewes, A. C. Doherty, A. Blais, P. Bertet, D. Vion, D. Esteve. 2011-04-27. Circuit QED with a Nonlinear Resonator : ac-Stark Shift and Dephasing. https://doi.org/10.1103/physrevlett.106.167002

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