Ground State of a Spin System with Two- and Four-spin Exchange Interactions on the Triangular Lattice

TL;DR

This paper investigates a triangular lattice spin system with two- and four-spin exchanges, revealing a four-sublattice ground state, potential finite-temperature phase transition with scalar chirality, and multiple magnetic field-induced phase transitions.

Contribution

It introduces a mean-field analysis of a spin model with four-spin exchange interactions, highlighting the emergence of a four-sublattice state and complex phase transitions.

Findings

Four-sublattice ground state favored by four-spin exchange

Predicted phase transition at finite temperature with scalar chirality

Magnetic field induces various phase transitions

Abstract

We study a spin system with both two- and four-spin exchange interactions on the triangular lattice as a possible model for the nuclear magnetism of solid $^3$He layers adsorbed on grafoil. The ground state is analyzed by the use of the mean-field approximation. It is shown that the four-sublattice state is favored by introduction of the four-spin exchange interaction. A possible phase transition at a finite temperature into a phase with the scalar chirality is predicted. Application of a magnetic field is shown to cause a variety of phase transitions.