Anisotropic scaling in YBa2Cu3O7 crystals with columnar defects

TL;DR

This paper investigates how anisotropic properties and columnar defects influence vortex pinning in YBa2Cu3O7 crystals, revealing temperature and field-dependent behaviors and demonstrating a rescaling method to recover uniaxial effects.

Contribution

It introduces an anisotropic rescaling approach to analyze the interplay between anisotropy and columnar defect pinning in high-temperature superconductors.

Findings

Peak in magnetization at high T and H indicates strong columnar defect pinning.

Rescaling method recovers uniaxial effects at low T and high H.

Scaling fails at low H, highlighting limitations of the approach.

Abstract

We explore the interplay between the mass anisotropy and the uniaxial pinning of tilted columnar defects (CD) in a YBa2Cu3O7 single crystal. At high temperatures T and fields H a sharp peak in the irreversible magnetization Mi at the direction of the tracks signals the presence of the CD. At low T such a peak is not observed, and the influence of the CD appears only as a perturbation to the angular dependence due to the anisotropy. We show that at low T and high H the uniaxial effects due to CD can be recovered by performing an anisotropic rescaling. As expected, this scaling fails at low H.