Synchronization and spin-flop transitions for a mean-field XY model in random field

TL;DR

This paper analyzes the phase transitions and magnetic ordering in a mean-field XY model subjected to a unidirectional random field, revealing spin-flop transitions and phase behavior at different temperatures.

Contribution

It characterizes the phase space and stationary solutions of the model, identifying conditions for phase transitions and spin-flop phenomena in the presence of a random field.

Findings

Magnetic ordering appears perpendicular to the field at low temperature.

Phase transitions depend on interaction strength and random field intensity.

Spin-flop transition occurs under certain conditions.

Abstract

We characterize the phase space for the infinite volume limit of a ferromagnetic mean-field XY model in a random field pointing in one direction with two symmetric values. We determine the stationary solutions and detect possible phase transitions in the interaction strength for fixed random field intensity. We show that at low temperature magnetic ordering appears perpendicularly to the field. The latter situation corresponds to a spin-flop transition.