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Measuring the quality factor of a microwave cavity using superconduting qubit devices

Yu-xi Liu·L. F. Wei·Franco Nori
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Abstract

We propose a method to create superpositions of two macroscopic quantum states of a single-mode microwave cavity field interacting with a superconducting charge qubit. The decoherence of such superpositions can be determined by measuring either the Wigner function of the cavity field or the charge qubit states. Then the quality factor Q of the cavity can be inferred from the decoherence of the superposed states. The proposed method is experimentally realizable within current technology even when the $Q$ value is relatively low, and the interaction between the qubit and the cavity field is weak.

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Yu-xi Liu, L. F. Wei, Franco Nori. 2005-11-17. Measuring the quality factor of a microwave cavity using superconduting qubit devices. https://doi.org/10.1103/physreva.72.033818

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