Magnetic-Field Induced First-Order Transition in the Frustrated XY Model on a Stacked Triangular Lattice

TL;DR

This study uses Monte Carlo simulations to investigate magnetic-field induced phase transitions in a frustrated XY model on a stacked triangular lattice, revealing a weakly first-order transition and insights into critical behavior at the Néel temperature.

Contribution

It clarifies the nature of the Potts-like transition and advances understanding of critical phenomena in frustrated magnetic systems.

Findings

Low-field transition is very weakly first order.

Behavior suggests tricriticality at zero field.

Provides clarification on the nature of the Potts-like transition.

Abstract

The results of extensive Monte Carlo simulations of magnetic-field induced transitions in the xy model on a stacked triangular lattice with antiferromagnetic intraplane and ferromagnetic interplane interactions are discussed. A low-field transition from the paramagnetic to a 3-state (Potts) phase is found to be very weakly first order with behavior suggesting tricriticality at zero field. In addition to clarifying some long-standing ambiguity concerning the nature of this Potts-like transition, the present work also serves to further our understanding of the critical behavior at $T_N$, about which there has been much controversy.