Exciton condensate at a total filling factor of 1 in Corbino 2D electron bilayers

TL;DR

This study demonstrates the formation of an exciton condensate in a Corbino 2D electron bilayer at total filling factor 1, evidenced by equal drag and drive voltages and a vanishing conductance at low temperatures, indicating excitonic superfluidity.

Contribution

It provides experimental evidence of exciton condensation in a Corbino geometry at v_tot=1 through magneto-transport and drag measurements, highlighting the conditions for excitonic superfluidity.

Findings

Drag voltage equals drive voltage at v_tot=1

Conductance vanishes at T->0 K and strong interlayer coupling

Presence of an excitonic circular current

Abstract

Magneto-transport and drag measurements on a quasi-Corbino 2D electron bilayer at the systems total filling factor 1 (v_tot=1) reveal a drag voltage that is equal in magnitude to the drive voltage as soon as the two layers begin to form the expected v_tot=1 exciton condensate. The identity of both voltages remains present even at elevated temperatures of 0.25 K. The conductance in the current carrying layer vanishes only in the limit of strong coupling between the two layers and at T->0 K which suggests the presence of an excitonic circular current.