Coherent Excited States in Superconductors due to a Microwave Field
Coherent Excited States in Superconductors due to a Microwave Field
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 ${\ensuremath{\omega}}_{0}$, steps at …