Chiral glass: a new equilibrium phase of ceramic high-Tc superconductors

TL;DR

This paper introduces the concept of a chiral-glass phase in ceramic high-Tc superconductors, demonstrating its stability through Monte Carlo simulations and analyzing its critical properties.

Contribution

It presents the first theoretical evidence for a stable chiral-glass phase in ceramic superconductors with d-wave pairing symmetry, supported by Monte Carlo simulations and finite-size scaling.

Findings

Chiral-glass phase is stable even with screening effects.

Critical exponents for the transition are estimated as ν_CG=1.3±0.2 and η_CG=-0.2±0.2.

Phase diagram and experimental implications are discussed.

Abstract

Possible occurrence of an equilibrium thermodynamic phase with a spontaneously broken time-reversal symmetry is studied in a model ceramic superconductor with anisotropic pairing symmetry. It is shown by Monte Carlo simulations that such a ``chiral-glass'' phase is truly stable even under the influence of screening. Existence of frustration in zero external field, arising from the d-wave pairing symmetry of high-T_c superconductors, is essential to realize this phase. Via a finite-size scaling analysis, critical exponents associated with the chiral-glass transition are estimated to be \nu _CG=1.3\pm 0.2 and \eta _CG=-0.2\pm 0.2. These values turn out to be close to those of the Ising spin glass. Phase diagram of the model is constructed and the implications to experiments are discussed.