Excitonic condensate and quasiparticle transport in electron-hole bilayer systems

TL;DR

This paper investigates the transport properties of excitonic condensates in electron-hole bilayer systems, highlighting phenomena like drag, counterflow, Josephson effects, and noise, to understand superfluid behavior and electromagnetic coupling.

Contribution

It introduces a phenomenological model that accounts for both condensate and quasiparticle contributions to transport in dipolar excitonic systems.

Findings

Identification of drag and counterflow transport behaviors.

Observation of in-plane Josephson effect signatures.

Analysis of noise as a measure of superfluid velocity.

Abstract

Bilayer electron-hole systems undergo excitonic condensation when the distance d between the layers is smaller than the typical distance between particles within a layer. All excitons in this condensate have a fixed dipole moment which points perpendicular to the layers, and therefore this condensate of dipoles couples to external electromagnetic fields. We study the transport properties of this dipolar condensate system based on a phenomenological model which takes into account contributions from the condensate and quasiparticles. We discuss, in particular, the drag and counterflow transport, in-plane Josephson effect, and noise in the in-plane currents in the condensate state which provides a direct measure of the superfluid collective-mode velocity.