Spin Model for Inverse Melting and Inverse Glass Transition

TL;DR

This paper introduces a spin model that captures inverse melting and inverse glass transition phenomena, providing analytical solutions and revealing regimes of phase transitions that resemble real inverse melting behaviors.

Contribution

It presents a novel spin model with degeneracy effects that explain inverse melting and glass transitions, including analytical solutions for both constant and random exchange interactions.

Findings

Model exhibits inverse melting and inverse glass transition behaviors.

Analytical solutions for both deterministic and random exchange interactions.

Identification of first and second order transition regimes.

Abstract

A spin model that displays inverse melting and inverse glass transition is presented and analyzed. Strong degeneracy of the interacting states of an individual spin leads to entropic preference of the "ferromagnetic" phase, while lower energy associated with the non-interacting states yields a "paramagnetic" phase as temperature decreases. An infinite range model is solved analytically for constant paramagnetic exchange interaction, while for its random exchange, analogous results based on the replica symmetric solution are presented. The qualitative features of this model are shown to resemble a large class of inverse melting phenomena. First and second order transition regimes are identified.