Exciton Transport in a Bilayer Quantum Hall Superfluid
  Bilayer quantum Hall systems at \nu =1 support an excitonic ground state. In addition to the usual charged quasiparticles, this system possesses a condensate degree of freedom: exciton transport. Detection of this neutral transport mode is facilitated by the use of the Corbino multiply-connected geometry in which charge transport is suppressed. We here summarize our recent experiments on Corbino devices which directly demonstrate exciton transport across the bulk of the incompressible \nu =1 quantum Hall state. 
J.P. Eisenstein, A.D.K. Finck, D. Nandi, L.N. Pfeiffer and K.W. West
cond-mat.mes-hall