Non-analytic behavior of 2D itinerant ferromagnets

TL;DR

This paper investigates the nature of phase transitions in 2D itinerant ferromagnets near zero temperature, revealing non-analyticities that can lead to first-order transitions or intermediate phases, challenging the conventional second-order transition paradigm.

Contribution

It demonstrates that non-analyticities in free energy and susceptibilities alter the transition order in 2D itinerant ferromagnets, providing new insights into their phase behavior.

Findings

Transition becomes first-order or involves an intermediate spiral phase

Non-analyticities in susceptibilities are crucial for transition behavior

Second-order transition is destroyed by non-analytic effects

Abstract

We consider an ordered ferromagnet in the vicinity of a T=0 transition into a paramagnet. We show that the free energy and the transverse and longitudinal static susceptibilities contain non-analyticities which destroy a continuous second-order transition. Depending on the parameters, the transition either becomes first-order, or occurs via an intermediate spiral phase.