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

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.
Comment: Final author version. 6 figures. Minor changes in this version include slightly expanded discussion of the peak in the momentum density in the supplemental material. Supplemental material is available on arXiv via the ancillary files attached to this submission