A condition for first order phase transitions in quantum mechanical tunneling models

TL;DR

This paper derives a criterion to identify parameter regions where first order phase transitions occur in quantum tunneling models, and validates it across various models including those related to spin tunneling in macroscopic particles.

Contribution

It introduces a new, rigorous criterion for first order phase transitions in quantum tunneling models, validated against existing heuristic results.

Findings

The criterion accurately predicts transition domains in tested models.

Agreement with previous heuristic determinations confirms the criterion's validity.

Applicable to models involving spin tunneling in macroscopic particles.

Abstract

A criterion is derived for the determination of parameter domains of first order phase transitions in quantum mechanical tunneling models. The criterion is tested by application to various models, in particular to some which have been used recently to explore spin tunneling in macroscopic particles. In each case agreement is found with previously heuristically determined domains.