Critical doping in overdoped high-Tc superconductors - a Quantum Critical Point?

TL;DR

This paper presents evidence for a quantum critical point in overdoped high-Tc superconductors, where multiple physical properties sharply peak and the pseudogap energy vanishes, potentially explaining their non-Fermi liquid behavior.

Contribution

It provides experimental evidence linking a critical doping point to a quantum critical point in high-Tc superconductors, suggesting a unified explanation for their anomalous properties.

Findings

Sharp peaks in physical properties at critical doping

Pseudogap energy drops to zero at this point

Supports quantum critical point scenario for HTSC behavior

Abstract

Evidence is presented from the scaling of the Knight shift, entropy and transport properties together with the sharp peaking of condensation energy, critical currents, superfluid density and a variety of other physical properties for the occurrence of a common critical doping point in lightly overdoped high-Tc superconductors (HTS). This critical doping lies at the point where the doping-dependent normal-state pseudogap energy, Eg, falls to zero and bears a strong, though incomplete, resemblance to a quantum critical point (QCP). A QCP scenario could lead directly to an explanation of the non-Fermi liquid behaviour of the normal-state metallic phase and the overall generic behaviour of the HTSC.