Aspects of quantum phase transitions

TL;DR

This paper provides a unified theoretical framework for understanding both classical and quantum phase transitions, emphasizing the relationship between thermodynamic and quantum concepts, illustrated through an exactly solvable model.

Contribution

It introduces a novel unified description of classical and quantum phase transitions using thermodynamic and quantum parameters, supported by an exactly solvable model.

Findings

Unified framework for classical and quantum phase transitions

Illustration using an exactly solvable model

Insights into the interplay between thermodynamic and quantum concepts

Abstract

A unified description of i) classical phase transitions and their remnants in finite systems and ii) quantum phase transitions is presented. The ensuing discussion relies on the interplay between, on the one hand, the thermodynamic concepts of temperature and specific heat and on the other, the quantal ones of coupling strengths in the Hamiltonian. Our considerations are illustrated in an exactly solvable model of Plastino and Moszkowski [Il Nuovo Cimento {\bf 47}, 470 (1978)].