Superfluidity of electron-hole pairs in randomly inhomogeneous bilayer   systems
  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. 
A. I. Bezuglyj, S. I. Shevchenko
cond-mat.mes-hall