Incommensurate vortices and phase transitions in two-dimensional XY models with interaction having auxiliary minima

TL;DR

This paper investigates the phase diagrams of 2D XY models with nonmonotonic interactions, exploring the potential for phase transitions involving fractional vortex dissociation when the interaction function includes auxiliary minima.

Contribution

It introduces a study of 2D XY models with nonmonotonic interactions, analyzing the conditions for phase transitions related to fractional vortex dissociation for q > 2.

Findings

Phase diagrams can include phase transitions involving fractional vortices.

Nonmonotonic interaction functions lead to complex vortex behaviors.

Potential for new types of phase transitions in XY models with auxiliary minima.

Abstract

We discuss if phase diagrams of the two-dimensional XY models in which the interaction of nearest planar spins is a nonmonotonic function of the angle u between them, V(u) = - Jcos(u) - Kcos(qu) can include a phase transition related to the dissociation of pairs of fractional vortices when q > 2.