Crystallization in mass-asymmetric electron-hole bilayers

TL;DR

This study investigates how mass asymmetry in electron-hole bilayers affects their structural phases, revealing a transition from homogeneous to localized hole arrangements as the mass ratio increases, using path integral Monte Carlo simulations.

Contribution

It introduces a detailed analysis of mass asymmetry effects on electron-hole bilayers with first-principles quantum simulations, highlighting a transition in hole localization.

Findings

Electrons remain nearly homogeneous across mass ratios.

Holes transition from homogeneous to localized as mass ratio increases.

Structural changes are consistent in both mesoscopic and macroscopic systems.

Abstract

We consider a \textit{mass-asymmetric} electron and hole bilayer. Electron and hole Coulomb correlations and electron and hole quantum effects are treated on first princles by path integral Monte Carlo methods. For a fixed layer separation we vary the mass ratio $M$ of holes and electrons between 1 and 100 and analyze the structural changes in the system. While, for the chosen density, the electrons are in a nearly homogeneous state, the hole arrangement changes from homogeneous to localized, with increasing $M$ which is verified for both, mesoscopic bilayers in a parabolic trap and for a macroscopic system.