Quantum Monte Carlo Study of Random Antiferromagnetic Heisenberg Chain

TL;DR

This paper uses quantum Monte Carlo simulations to analyze how randomness affects spin-1/2 and 1 antiferromagnetic Heisenberg chains, providing detailed phase diagrams and methodological advancements.

Contribution

It introduces a generalized continuous-time loop algorithm for higher-S spins and offers precise calculations of key physical quantities under randomness.

Findings

Identified phases and phase transitions in random antiferromagnetic chains.

Calculated uniform susceptibility, string order parameter, and correlation lengths.

Developed a generalized algorithm for higher-spin systems.

Abstract

Effects of randomness on the spin-1/2 and 1 antiferromagnetic Heisenberg chains are studied using the quantum Monte Carlo method with the continuous-time loop algorithm. We precisely calculated the uniform susceptibility, string order parameter, spatial and temporal correlation length, and the dynamical exponent, and obtained a phase diagram. The generalization of the continuous-time loop algorithm for the systems with higher-S spins is also presented.