Exciton and biexciton energies in bilayer systems

TL;DR

This paper calculates exciton and biexciton energies in ideal 2D bilayer systems, revealing how their binding energies depend on layer separation using numerical and quantum Monte Carlo methods.

Contribution

It introduces a combined numerical and quantum Monte Carlo approach to accurately compute exciton and biexciton energies in bilayer systems.

Findings

Exciton binding energy decays as inverse layer separation.

Biexciton binding energy decays exponentially with layer separation.

Provides quantitative data on exciton and biexciton energies.

Abstract

We report calculations of the energies of excitons and biexcitons in ideal two-dimensional bilayer systems within the effective-mass approximation with isotropic electron and hole masses. The exciton energies are obtained by a simple numerical integration technique, while the biexciton energies are obtained from diffusion quantum Monte Carlo calculations. The exciton binding energy decays as the inverse of the separation of the layers, while the binding energy of the biexciton with respect to dissociation into two separate excitons decays exponentially.