Transport properties of an electron-hole bilayer/superconductor hybrid junction

Abstract

We investigate the transport properties of a junction consisting of an electron-hole bilayer in contact with normal and superconducting leads. The electron-hole bilayer is considered as a semi-metal with two electronic bands. We assume that in the region between the contacts the system hosts an exciton condensate described by a BCS-like model with a gap $\Gamma$ in the quasiparticle density of states. We first discuss how the subgap electronic transport through the junction is mainly governed by the interplay between two kinds of reflection processes at the interfaces: The standard Andreev reflection at the interface between the superconductor and the exciton condensate, and a coherent crossed reflection at the semi-metal/exciton-condensate interface that converts electrons from one layer into the other. We show that the differential conductance of the junction shows a minimum at voltages of the order of $\Gamma /e$. Such a minimum can be seen as a direct hallmark of the existence of the gapped excitonic state.

References in corpus (8)

• Specular Andreev reflection in graphene
• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
• Coulomb Drag in the Exciton Regime in Electron-Hole Bilayers
• Anomalous Coulomb drag in electron-hole bilayers
• Giant Frictional Drag in Double Bilayer Graphene Heterostructures
• Transport in two-dimensional disordered semimetals
• Coherent transport in homojunction between excitonic insulator and semimetal
• Variable resistance at the boundary between semimetal and excitonic insulator

Cited by in corpus (2)

• Andreev-Coulomb Drag in Coupled Quantum Dots
• Quantum Transport Properties of an Exciton Insulator/Superconductor Hybrid Junction