Anisotropic Rescaling of a Splayed Pinning Landscape in Hg Cuprates: Strong Vortex Pinning and Recovery of Variable Range Hopping

Abstract

Strong vortex pinning by fission-induced uniformly splayed columnar tracks in anisotropic mercury cuprates is demonstrated to result from (re)scaling of the pinning landscape by a large superconducting anisotropy. The effective ``narrowing'' of the splay distribution restores variable range vortex hopping (VRH) motion expected for nearly parallel pins. VRH emerges as a distinctive peak in the vortex creep rate ( $\ensuremath{\sim}12%$ at low fields at $T/{T}_{c}\ensuremath{\sim}0.5$) of the most anisotropic ${\mathrm{HgBa}}_{2}{\mathrm{Ca}}_{2}{\mathrm{Cu}}_{3}\mathrm{O}{}_{8+\ensuremath{\delta}}$, a peak well described by a glassy dynamics with the characteristic exponent $\ensuremath{\mu}\ensuremath{\sim}1/3$.