Photon-induced superconducting phase transition in some cuprates

Abstract

Recent observations of photo-induced transient superconductivity in some cuprate systems which are otherwise in a semiconducting or insulating state are explained on the basis of a theoretical model which was suggested by us over two and a half decades ago. In these systems, the radiation field quanta play a dual role. In the first they produce carriers and in the second role they take part in the pairing process along with virtual exchange of other boson modes, i.e. phonons or electronic boson modes. Owing to the two-boson nature the coupling constant λ_rb depends on the photon density (photoexcitations) impressed on the system. The relative role of the photoresponse time and the relaxation (recombination) time are important in producing the metallic and superconducting state.