2018/05/31 by Thibault Capelle, Emmanuel Flurin, Edouard Ivanov +8
Physics and Astronomy · #quant-ph #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevapplied.13.034022
published as Phys. Rev. Applied 13, 034022 (2020)
arxiv created 2019/12/23 · arxiv updated 2020/03/18
Although the main loss channel of planar microwave superconducting resonators has been identified to be related to an external coupling to a two-level system (TLS) bath, the behavior of such a cavity in the presence of an off-resonant pump has yet to be fully understood. Here a semi-classical model that predicts a power-dependent frequency shift besides the well-known TLS-induced damping is derived. The model is validated experimentally by performing a two-tone spectroscopy of several resonators fabricated on various substrates. Together with the provided analytic formulas, the technique proposed here is a simple, yet powerful, tool to characterize various properties of the TLS bath, such as their average dephasing rate.