Trion formation in a two-dimensional hole-doped electron gas

TL;DR

This study uses quantum Monte Carlo simulations to investigate how a single hole interacts with a 2D electron gas, revealing a transition from collective excitons to trion states consistent with experimental observations.

Contribution

It provides the first detailed numerical evidence of a crossover from Mahan excitons to trion formation in a 2D hole-doped electron gas.

Findings

Evidence of a crossover from excitons to trions

Agreement with experimental data on quantum wells

Quantitative analysis of correlation energies and pair correlations

Abstract

The interaction between a single hole and a two-dimensional, paramagnetic, homogeneous electron gas is studied using diffusion quantum Monte Carlo simulations. Calculations of the electron-hole correlation energy, pair-correlation function, and the electron-hole center-of-mass momentum density are reported for a range of electron--hole mass ratios and electron densities. We find numerical evidence of a crossover from a collective Mahan exciton to a trion-dominated state in a density range in agreement with that found in recent experiments on quantum well heterostructures.