Superfluidity of electron-hole pairs in randomly inhomogeneous bilayer systems

TL;DR

This paper investigates how random inhomogeneities like impurities and layer roughness affect the superfluidity of electron-hole pairs in bilayer systems under strong magnetic fields, showing that such imperfections decrease superfluid current and transition temperature.

Contribution

It provides a theoretical analysis of the impact of inhomogeneities on superfluid properties in bilayer electron-hole systems in high magnetic fields.

Findings

Impurities and roughness reduce superfluid current density.

Fluctuations in interlayer distance lower the superfluid transition temperature.

Superfluidity is sensitive to inhomogeneities when interlayer distance is near the magnetic length.

Abstract

In bilayer systems electron-hole (e-h) pairs with spatially separated components (i.e., with electrons in one layer and holes in the other) can be condensed to a superfluid state when the temperature is lowered. This article deals with the influence of randomly distributed inhomogeneities on the superfluid properties of such bilayer systems in a strong perpendicular magnetic field. Ionized impurities and roughenings of the conducting layers are shown to decrease the superfluid current density of the e-h pairs. When the interlayer distance is smaller than or close to the magnetic length, the fluctuations of the interlayer distance considerably reduce the superfluid transition temperature.