Finite-temperature phase transitions in the quantum fully frustrated Ising models

TL;DR

This paper investigates finite-temperature phase transitions in quantum fully frustrated Ising models on triangular and square lattices, revealing how transition temperatures depend on the transverse magnetic field strength.

Contribution

It introduces an exact mapping of quantum frustrated Ising models onto classical models with complex interactions, enabling analysis of phase transitions at finite temperatures.

Findings

Transition temperatures are proportional to the transverse field in weak-field regimes.

The models exhibit critical phases separated by phase transitions.

The approach provides a new way to analyze quantum frustrated systems.

Abstract

The quantum antiferromagnetic spin-1/2 Ising model on a triangular lattice and analogous fully frustrated Ising model on a square lattice with quantum fluctuations induced by the application of the transverse magnetic field are studied at finite temperatures by constructing an exact mapping onto a purely classical model with a more complex interaction. It is shown that in weak fields the temperatures of the phase transitions separating the critical phase from the ordered and disordered phases in both models are proportional to the magnitude of the field.