Critical currents and giant non-dissipative drag for superfluid electron–hole pairs inquantum Hall multilayers

Abstract

Superfluid properties of electron–hole pairs in a quantum Hall four-layer system areinvestigated. The system is considered as a solid-state realization of a two-componentsuperfluid Bose gas with dipole–dipole interaction. One superfluid component is formed inthe top bilayer and the other component—in the bottom one. We obtain the dispersionequation for the collective mode spectrum and compute the critical parameters(the critical interlayer distance and the critical currents) versus the filling factor.We find that the critical currents of the components depend on each other. Themaximum critical current of a given component can be reached if the current of theother component is equal to zero. The non-dissipative drag effect between thecomponents is studied. It is shown that in the system considered the drag factor is verylarge. Under appropriate conditions it can be about 10%, which is at least threeorders of magnitude larger than one predicted for two-component atomic Bosegases.