Absence of anisotropic universal transport in YBCO

TL;DR

This paper investigates the lack of observed anisotropic universal transport in YBCO, despite known anisotropies in other properties, and offers an explanation for this discrepancy.

Contribution

It provides a possible explanation for why anisotropy is absent in universal transport measurements in YBCO, contrasting with anisotropies seen in other properties.

Findings

Universal transport in YBCO shows no significant anisotropy.

The paper explains the discrepancy between anisotropic properties and isotropic universal transport.

It discusses recent experimental results confirming isotropic universal transport.

Abstract

There exists significant in-plane anisotropy between $a$ and $b$ axis for various properties in YBCO. However recent thermal conductivity measurement by Chiao et al. which confirms previous microwave conductivity measurement by Zhang et al., shows no obvious anisotropy in the context of universal transport. We give a possible explanation of why the anisotropy is seen in most properties but not seen in the universal transport.