Effect of Impurities on the Electronic Structure of Vortex Core Investigated by Microwave Surface Impedance Measurement

Abstract

We investigated the microwave surface impedance in Zn doped YBa 2 Cu 3 O y . For low Zn concentrations, crossover frequency ω p and viscosity η of vortex do not change significantly (at maximum, factor of 2). This is in sharp contrast to the dramatic change in the zero-field quasiparticle scattering time. The robust nature of viscosity on the impurity doping suggests that the quasi-particle scattering time in the vortex core is determined by a different mechanism from that outside the core.