Diamagnetism and flux creep in bilayer exciton superfluids

Abstract

We discuss the diamagnetism induced in an isolated quantum Hall bilayer with total filling factor ν T = 1 by an in-plane magnetic field. This is a signature of counterflow superfluidity in these systems. We calculate magnetically induced currents in the presence of pinned vortices nucleated by charge disorder, and we predict a history-dependent diamagnetism that could persist on laboratory time scales. For current samples, we find that the maximum in-plane moment is small, but with stronger tunneling the moments would be measurable using torque magnetometry. Such experiments would allow the persistent currents of a counterflow superfluid to be observed in an electrically isolated bilayer.

Coherent exciton transport in semiconductors

“…Interesting theoretical predictions concern the response of the bilayer exciton condensate to external electromagnetic fields [16,121,249,67] and impurities [66], as well as the transport properties of hybrid circuits including exciton condensates and superconductors [62,197,248]. For weak inter-layer interaction or filling factors other than ν T = 1, bilayers are predicted to undergo phase transitions to other strongly correlated phases, such as paired two-dimensional Laughlin liquids and Wigner solids [290], or peculiar excitonic charge density waves [48].…”

Theory for electric dipole superconductivity with an application for bilayer excitons

“…So there is an essential difference between the electric dipole superconductor and the exciton superfluid. In addition, a few previous works have investigated the dipole superfluid 16 17 30 31 . For example, Balatsky et al investigated the bilayer exciton system under an in-plane magnetic field and found that the phase of the condensate can couple to the gradient of the vector potential.…”