Electron-Hole Liquid in the Couple Quantum Wells

TL;DR

This paper demonstrates that in coupled quantum wells, the homogeneous electron-hole system becomes unstable at low densities due to Coulomb correlations, leading to the formation of inhomogeneous electron-hole liquid drops.

Contribution

It reveals the instability mechanism in coupled quantum wells caused by many-body Coulomb correlations and predicts the formation of electron-hole liquid drops at low densities.

Findings

Homogeneous electron-hole system becomes unstable below a critical density.

Coulomb correlations induce positive compressibility and instability.

Formation of inhomogeneous electron-hole liquid drops occurs at low densities.

Abstract

It is shown that the homogeneous state of the spatially separated electrons and holes in the coupled quantum wells (CQW) is instable if the layer charge density is smaller than the critical value specified by the parameters of the CQW. The effect is due to the many-body Coulomb correlations which provide the positive compressibility. The instability results in the formation of the inhomogeneous system which comprises the liquid electron-hole drops.