Quantum Critical Point, Scaling, and Universality in High Tc [CaxLa(1-x)][Ba(2-c-x)La(c+x)]Cu3Oy

TL;DR

This study investigates the presence of a quantum critical point in a high-temperature superconductor using charge transport measurements, questioning existing theoretical relations and proposing further experiments for clarification.

Contribution

The paper provides experimental insights into the absence of a quantum critical point in CLBLCO and suggests refining the understanding of Homes' relation in high-Tc superconductors.

Findings

No evidence of the expected quantum critical point in CLBLCO

Charge transport data challenge the current interpretation of Homes' relation

Further experiments on YBCO are proposed to clarify these findings

Abstract

Using charge transport observations on sintered ceramic samples of CLBLCO, we failed to observe the Quantum Critical Point (QCP) where it is expected. Experimental data relating Cooper pair density, electrical conductivity, and superconductivity critical temperature suggest that Homes' relation might need a more specific definition of 'sigma'. Transport observations on YBCO single crystals will resolve this question.