Monte Carlo Simulations of Doped, Diluted Magnetic Semiconductors - a System with Two Length Scales

TL;DR

This paper uses Monte Carlo simulations to explore the magnetic phase diagram of doped diluted magnetic semiconductors, revealing quantum effects and the need for specialized algorithms due to a wide interaction strength distribution.

Contribution

It introduces a discrete spin model that approximates the quantum system and demonstrates the importance of cluster algorithms for accurate simulation.

Findings

Strong quantum effects observed in the ordered phase.

Long relaxation times necessitate specialized cluster algorithms.

Results highlight the impact of interaction strength distribution.

Abstract

We describe a Monte Carlo simulation study of the magnetic phase diagram of diluted magnetic semiconductors doped with shallow impurities in the low concentration regime. We show that because of a wide distribution of interaction strengths, the system exhibits strong quantum effects in the magnetically ordered phase. A discrete spin model, found to closely approximate the quantum system, shows long relaxation times, and the need for specialized cluster algorithms for updating spin configurations. Results for a representative system are presented.