Optically induced magnetic relaxation in Bi-2212 single crystals

A significant increase of the magnetic relaxation rate was observed in superconducting Bi-2212 single crystals at helium temperatures under the influence of visible light with an intensity 10−4−101 mW cm−2. To a first approximation, the change of the magnetic moment is proportional to the dose of incident light. The breaking of Cooper pairs under illumination, as well as interaction between the vortices and optical phonons produced during recombination of the quasiparticles, may be the reasons for the effect observed. The relaxation time of the hot electrons produced under the action of light was estimated to be about 5 × 10−8s.