Longitudinal Current Dissipation in Bose-glass Superconductors

Abstract

A scaling theory of vortex motion in Bose glass superconductors with currents parallel to the common direction of the magnetic field and columnar defects is presented. Above the Bose-glass transition the longitudinal DC resistivity $ρ_{||}(T)\sim (T-T_{BG})^{ν' z'}$ vanishes much faster than the corresponding transverse resistivity $ρ_{\perp}(T)\sim (T-T_{BG})^{ν' (z'-2)}$, thus {\it reversing} the usual anisotropy of electrical transport in the normal state of layered superconductors. In the presence of a current $\bf J$ at an angle $θ_J$ with the common field and columnar defect axis, the electric field angle $θ_E$ approaches $π/2$ as $T\rightarrow T_{BG}^+$. Scaling also predicts the behavior of penetration depths for the AC currents as $T\rightarrow T_{BG}^-$, and implies a {\it jump discontinuity} at $T_{BG}$ in the superfluid density describing transport parallel to the columns.