Critical current density of hole doped high-Tc cuprates and heavy fermion superconductors: relevance to the possible quantum critical behavior

TL;DR

This paper explores the relationship between critical current density in hole-doped cuprates and heavy fermion superconductors, highlighting potential quantum critical behavior influencing superconductivity across different material classes.

Contribution

It identifies a possible universal link between quantum critical points and maximum critical current densities in both cuprates and heavy fermion systems.

Findings

Peak Jc at p ~ 0.185 in cuprates suggests a quantum critical point.

Maximum Tc and Ic at critical pressure in heavy fermions indicate quantum criticality.

Resemblance in behavior supports quantum critical physics' role in superconductivity.

Abstract

The superconducting critical current density, Jc, in hole doped cuprates show strong dependence on the doped hole content, p, within the copper oxide plane(s). The doping dependent Jc mainly exhibits the variation of the intrinsic depairing critical current density as p is varied. Jc(p) tends to peak at p ~ 0.185 in copper oxide superconductors. This particular value of the hole content, often termed as the critical hole concentration, has several features putative to a quantum critical point (QCP). Very recently, pressure dependences of the superconducting transition temperature (Tc) and the critical current (Ic) in pure CeRhIn5 and Sn doped CeRhIn5 heavy fermion compounds have been reported (Nature Communications (2018) 9:44, DOI: 10.1038/s41467-018-02899-5). The critical pressure demarcates an antiferromagnetic quantum critical point where both Tc and Ic are maximized. We have compared and contrasted this behavior with those found for Y1-xCaxBa2Cu3O7-d in this brief communication. The resemblance of the systematic behavior of the critical current with pressure and hole content between heavy fermion systems and hole doped cuprates is significant. This adds to the circumstantial evidence that quantum critical physics probably plays a notable role beyond the unconventional normal and superconducting state properties of copper oxide superconductors.