Inhomogeneous Superconducting State and intrinsic Tc : Near Room Temperature Superconductivity in the Cuprates

TL;DR

This paper reviews evidence that inhomogeneous cuprate superconductors exhibit an intrinsic critical temperature near room temperature, significantly higher than the resistive transition temperature, due to embedded superconducting clusters.

Contribution

It introduces the concept of an intrinsic critical temperature in cuprates and discusses experimental evidence supporting its high value, close to room temperature.

Findings

Intrinsic Tc can reach near room temperature in some cuprates.

Superconducting clusters cause anomalous diamagnetism above resistive Tc.

Inhomogeneity affects the a.c. properties of cuprate superconductors.

Abstract

Doped cuprates are inhomogeneous superconductors. The concept of an intrinsic critical temperature, Tcintr.$\equiv$ Tc*, whose value greatly exceeds that for the resistive Tcres.$\equiv$ Tc, is supported by a number of experimental studies, including those performed recently. These data are discussed in this review. The anomalous diamagnetism observed at Tcres.$\equiv$ <T< Tc* is a manifestation of the presence of superconducting clusters embedded into a normal metallic matrix. The value of intrinsic critical temperature in some cuprates reaches a value which is close to room temperature. The a.c. properties of such inhomogeneous systems are discussed.