Unusual temperature behavior of entropy of antiferromagnetic spin state in nuclear matter with effective finite range interaction

TL;DR

This paper investigates the unusual increase in entropy at low temperatures for antiferromagnetic spin states in nuclear matter, linking it to effective mass dependencies and criteria violations.

Contribution

It reveals the cause of the unexpected entropy behavior in AFM states, emphasizing the role of effective mass and criteria violations at low temperatures.

Findings

Entropy of AFM state exceeds nonpolarized matter at low temperatures.

Violation of low temperature criteria explains the entropy anomaly.

Effective mass dependence is key to understanding the entropy behavior.

Abstract

The unusual temperature behavior of the entropy of the antiferromagnetic (AFM) spin state in symmetric nuclear matter with the Gogny D1S interaction, being larger at low temperatures than the entropy of nonpolarized matter, is related to the dependence of the entropy on the effective masses of nucleons in a spin polarized state. The corresponding conditions for comparing the entropies of the AFM and nonpolarized states in terms of the effective masses are formulated, including low and high temperature limits. It is shown that the unexpected temperature behavior of the entropy of the AFM spin state at low temperatures is caused by the violation of the corresponding low temperature criterium.