Vortex dynamics in inhomogeneous superconducting films

Abstract

A vortex moving without dissipation in a superconducting film containing random inhomogeneities is shown to have a strictly periodic trajectory. By exploiting a new percolation analogy, the voltage noise power and the electrical resistivity due to a vortex are described at low frequencies in the zero-drag limit by the universal form $P\left(\omega \right)\sim {\omega }^{p_2}$, with $p_2\simeq 0.4$. The introduction of dissipation into the vortex equations of motion modifies this form and causes resistivity to appear at zero frequency. Analogous effects should be observable in inhomogeneous superfluid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ films.