MAGNETOOPTICS OF TYPE-II SUPERCONDUCTORS

The magneto-optical activity of superconducting YBa2Cu3O7 observed by Karrai et al. is not present in many commonly employed models of vorte x dynamics. Here we propose a simple, unifying picture for the frequen cy-dependent magneto-optic response of type-II superconductors at low temperatures. We bring together Kohn's theorem, vortex core excitation s, and vortex pinning and damping into a single expression for the con ductivity tensor. The theory describes magneto-optical activity observ ed in infrared transmission measurements of thin films of YBa2Cu3O7.