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

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 ( $\sim 12\%$ at low fields at $T/T_c\sim 0.5$) of the most anisotropic ${\mathrm{HgBa}}_2{\mathrm{Ca}}_2{\mathrm{Cu}}_3\mathrm{O}{}_{8+\delta }$, a peak well described by a glassy dynamics with the characteristic exponent $\mu \sim 1/3$.