Manifestation of the bulk phase transition in the edge energy spectrum   in a two dimensional bilayer electron system
  We use a quasi-Corbino sample geometry with independent contacts to different edge states in the quantum Hall effect regime to investigate the edge energy spectrum of a bilayer electron system at total filling factor $\nu=2$. By analyzing non-linear $I-V$ curves in normal and tilted magnetic fields we conclude that the edge energy spectrum is in a close connection with the bulk one. At the bulk phase transition spin-singlet - canted antiferromagnetic phase $I-V$ curve becomes to be linear, indicating the disappearance or strong narrowing of the $\nu=1$ incompressible strip at the edge of the sample. 
E.V. Deviatov, A. Wurtz, A.Lorke, M.Yu. Melnikov, V.T. Dolgopolov, A.   Wixforth, K.L. Campman, A.C. Gossard