Binding energies and spatial structures of small carrier complexes in monolayer transition metal dichalcogenides via diffusion Monte Carlo

TL;DR

This paper uses diffusion Monte Carlo to accurately compute binding energies and spatial structures of excitons, trions, and biexcitons in monolayer transition metal dichalcogenides, comparing results with approximate methods and experiments.

Contribution

It provides a detailed analysis of small carrier complexes in 2D TMDCs using diffusion Monte Carlo, highlighting the accuracy and limitations of approximate approaches.

Findings

Diffusion Monte Carlo yields precise binding energies.

Approximate variational methods show both successes and failures.

Results align and differ from recent experimental data.

Abstract

Ground state diffusion Monte Carlo is used to investigate the binding energies and carrier probability distributions of excitons, trions, and biexcitons in a variety of two-dimensional transition metal dichalcogenide materials. We compare these results to approximate variational calculations, as well as to analogous Monte Carlo calculations performed with simplified carrier interaction potentials. Our results highlight the successes and failures of approximate approaches as well as the physical features that determine the stability of small carrier complexes in monolayer transition metal dichalcogenide materials. Lastly, we discuss points of agreement and disagreement with recent experiments.