Scaling of the Hall resistivity in epitaxialHgBa2CaCu2O6+δthin films with columnar defects

Abstract

We have studied the Hall scaling relation ${\ensuremath{\rho}}_{\mathrm{xy}}=A{\ensuremath{\rho}}_{\mathrm{xx}}^{\ensuremath{\beta}}$ for the mixed-state Hall effects of ${\mathrm{HgBa}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{6+\mathrm{\ensuremath{\delta}}}$ thin films before and after irradiation by high-energy Xe ions. \ensuremath{\beta} increases from $1.0\ifmmode\pm\else\textpm\fi{}0.1$ to $2.0\ifmmode\pm\else\textpm\fi{}0.1$ as a perpendicular magnetic field increases from 0 to 8 T, and increases from $1.0\ifmmode\pm\else\textpm\fi{}0.1$ to $1.5\ifmmode\pm\else\textpm\fi{}0.05$ as the angle between the columnar tracks and a 4 T field decreases from 75\ifmmode^\circ\else\textdegree\fi{} to 0\ifmmode^\circ\else\textdegree\fi{}. The observation of $\ensuremath{\beta}=1$ is consistent with a recent theory based on d-wave superconductivity, in which the Hall angle was predicted to show a universal behavior that was independent of the mean free path of charge carriers in the low-field region.