Dielectric Properties of the Quasi-Two-Dimensional Electron Liquid in Heterojunctions

TL;DR

This paper theoretically investigates the dielectric properties of a quasi-two-dimensional electron liquid at semiconductor heterojunctions, incorporating many-body effects and providing analytical expressions for practical use.

Contribution

It applies the self-consistent STLS local-field correction and a variational approach to accurately analyze the dielectric properties of Q2D electron liquids in heterojunctions.

Findings

Calculated dielectric function and plasmon dispersion for various densities

Analytical expressions fitted to numerical results

Considered charge distribution penetration effects

Abstract

A quasi-two-dimensional (Q2D) electron liquid (EL) is formed at the interface of a semiconductor heterojunction. For an accurate characterization of the Q2D EL, many-body effects need to be taken into account beyond the random phase approximation. In this theoretical work, the self-consistent static local-field correction known as STLS is applied for the analysis of the Q2D EL. The penetration of the charge distribution to the barrier-acting material is taken into consideration through a variational approach. The Coulomb from factor that describes the effective 2D interaction is rigorously treated. The longitudinal dielectric function and the plasmon dispersion of the Q2D EL are presented for a wide range of electron and ionized acceptor densities choosing GaAs/AlGaAs as the physical system. Analytical expressions fitted to our results are also supplied to enable a widespread use of these results.