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arXiv · 1603.02726

Coherent excited states in superconductors due to a microwave field

A. V. Semenov·I. A. Devyatov·P. J. de Visser·T. M. Klapwijk
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Abstract

We describe theoretically the depairing effect of a microwave field on diffusive s-wave superconductors. The ground state of the superconductor is altered qualitatively in analogy to the depairing due to a dc current. In contrast to dc-depairing the density of states acquires, for microwaves with frequency $ω_0$, steps at multiples of the photon energy $Δ\pm n\hbarω_0$ and shows an exponential-like tail in the subgap regime. We show that this ac-depairing explains the measured frequency shift of a superconducting resonator with microwave power at low temperatures.

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A. V. Semenov, I. A. Devyatov, P. J. de Visser, T. M. Klapwijk. 2016-07-20. Coherent excited states in superconductors due to a microwave field. https://doi.org/10.1103/physrevlett.117.047002

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