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Using a qubit to measure photon number statistics of a driven, thermal oscillator

A. A. Clerk·D. Wahyu Utami
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Abstract

We demonstrate theoretically how photon number statistics of a driven, damped oscillator at finite temperature can be extracted by measuring the dephasing spectrum of a two-level system dispersively coupled to the oscillator; we thus extend the work of Dykman (1987) and Gambetta et al. (2006). We carefully consider the fidelity of this scheme-- to what extent does the measurement reflect the initial number statistics of the mode? We also derive analytic results for the dephasing of a qubit by a driven, thermal mode, and compare results obtained at different levels of approximation. Our results have relevance both to experiments in circuit cavity QED, as well as to nano-electromechanical systems.

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A. A. Clerk, D. Wahyu Utami. 2006-12-09. Using a qubit to measure photon number statistics of a driven, thermal oscillator. https://doi.org/10.1103/physreva.75.042302

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