Phase Transitions of Frustrated XY spins in Two Dimensions

TL;DR

This paper investigates phase transitions in a frustrated 2D XY model on a triangular lattice, revealing a single transition with long-range interactions and a smectic-A like phase, advancing understanding of complex magnetic ordering.

Contribution

It introduces new variables that clarify the physics of C-IC transitions and shows how phase and chiral variables couple to produce long-range interactions.

Findings

A single transition occurs in the FFTXY model.

The dielectric constant diverges at the transition.

The C phase is a Smectic-A like phase that disorders via a 2D nematic-smectic-A transition.

Abstract

The row model is used to study the commensurate-incommensurate (C-IC) an isotropic (FFTXY) transitions of the frustrated 2D XY model on the triangular lattice. New relevant variables clarify the physics of these transitions: phase and chiral variables are coupled so that spin waves generate long range polar interactions. The resulting dielectric constan diverges at the transition. A single transition occurs for the FFTXY model; in the C-IC regime the Lifshitz point is at T=0 and the C phase i a Smectic-A like phase which disorders via a 2D nematic-smectic-A transition.