Spin Liquid Phases in 2D Frustrated XY Model

TL;DR

This paper investigates the existence and nature of spin liquid phases in the 2D frustrated XY model, combining spin wave analysis and variational methods to explore vortex behaviors and phase transitions.

Contribution

It introduces a semiclassical approach based on spin wave action and variational techniques to study vortex-induced phases in quantum and classical 2D XY models.

Findings

Spin liquid phase persists in quantum XY models.

Vortex liquid and crystal phases can emerge and relate to spin liquid states.

Vortex phases are linked to crystalline interpretations of the spin liquid.

Abstract

In this paper we consider the $J_1-J_2-J_3$ classical and quantum 2D XY model. Spin wave calculations show that a spin liquid phase still exists in the quantum case as for Heisenberg models. We formulate a semiclassical approach of these models based on spin wave action and use a variational method to study the role played by vortices. Liquid and crystal phases of vortex could emerge in this description. These phases seem to be directly correlated with the spin liquid one and to its crystalline interpretation.