Ginzburg-Landau theory of the cluster glass phase

TL;DR

This paper develops a Ginzburg-Landau theoretical framework to describe the low-temperature cluster glass phases in site-disordered magnets, revealing how transition lines and phases evolve with disorder and temperature.

Contribution

It introduces a Ginzburg-Landau free energy model based on a recent field theory for spin glasses, capturing the emergence of new phases at critical points in disordered magnetic systems.

Findings

Prefactors of cubic and quartic terms vary along the transition line.

Vanishing of these prefactors at specific points leads to new transition lines.

Classification of new phases based on the behavior of these terms.

Abstract

On the basis of a recent field theory for site-disordered spin glasses a Ginzburg-Landau free energy is proposed to describe the low temperatures glassy phase(s) of site-disordered magnets. The prefactors of the cubic and dominant quartic terms change gradually along the transition line in the concentration-temperature phase diagram. Either of them may vanish at certain points $(c_*, T_*)$, where new transition lines originate. The new phases are classified