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 {open_quotes}narrowing{close_quotes} 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 ({approximately}12{percent} at low fields at T/T{sub c}{approximately}0.5 ) of the most anisotropic HgBa{sub 2}Ca {sub 2}Cu{sub 3}Othinsp{sub 8+{delta}} , a peak well described by a glassy dynamics with the characteristic exponent {mu}{approximately}1/3 . {copyright} {ital 1998} {ital The American Physical Society }