Quantum Monte Carlo Simulations of the Impurity-Induced Phase Transitions in Low-Dimensional Magnets

TL;DR

This paper uses quantum Monte Carlo simulations to explore how magnetic and non-magnetic impurities induce phase transitions in low-dimensional quantum magnets, revealing a monotonic increase in transition temperature with impurity spin magnitude.

Contribution

It provides new insights into impurity-induced phase transitions in low-dimensional magnets using advanced quantum Monte Carlo techniques and local magnetic structure analysis.

Findings

Transition temperature increases monotonically with impurity spin magnitude

Valence-bond solid-like picture explains impurity effects

Local magnetic structures are significantly affected by impurities

Abstract

We study the impurity-induced phase transitions in a quasi-one-dimensional Heisenberg antiferromagnet doped with magnetic spin-1/2 impurities and non-magnetic ones. The impurity-induced transition temperature determined by the quantum Monte Carlo method with the continuous-time loop algorithm is monotonically increasing as a function of the magnitude of the impurity spin. To these results, we give discussions based on the valence-bond solid-like picture for the pure system and the inspection of the local magnetic structure around the impurities.