Photon-triggered instability in the flux flow regime of a strongly disordered superconducting strip

We study, theoretically, the single-photon response of a strongly disordered thin superconducting strip in the flux flow state. We find that this resistive state, at a current I larger than the critical current Ic, jumps to the normal state by the absorption of a single optical photon. The absorbed photon creates a beltlike region with suppressed superconductivity and fast moving Josephson-like vortices across the strip. The formed Josephson-like link is not stable in such a superconductor and evolves into a normal domain which expands along the length of the superconducting strip, leading to the transition to the normal state.