Semenov A V, Devyatov I A, de Visser P J, Klapwijk T M
Moscow State Pedagogical University, 1 Malaya Pirogovskaya Street, Moscow 119992, Russia.
Moscow Institute of Physics and Technology, Dolgoprudny, Moscow 141700, Russia.
Phys Rev Lett. 2016 Jul 22;117(4):047002. doi: 10.1103/PhysRevLett.117.047002. Epub 2016 Jul 19.
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±nℏω_{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.
我们从理论上描述了微波场对扩散型s波超导体的去配对效应。超导体的基态发生了定性改变，类似于直流电流导致的去配对情况。与直流去配对不同，对于频率为ω₀的微波，态密度在光子能量Δ±nℏω₀的倍数处出现台阶，并在能隙以下区域呈现出指数型尾部。我们表明，这种交流去配对解释了低温下超导谐振器在微波功率作用下测量到的频率偏移。
