A quantum Hall Mach-Zehnder interferometer far beyond the equilibrium
  We experimentally realize quantum Hall Mach-Zehnder interferometer which operates far beyond the equilibrium. The operation of the interferometer is based on allowed intra-edge elastic transitions within the same Landau sublevel in the regime of high imbalances between the co-propagating edge states. Since the every edge state is definitely connected with the certain Landau sublevel, the formation of the interference loop can be understood as a splitting and a further reconnection of a single edge state. We observe an Aharonov-Bohm type interference pattern even for low-size interferometers. This novel interference scheme demonstrates high visibility even at millivolt imbalances and survives in a wide temperature range. 
E.V. Deviatov, A. Ganczarczyk, A. Lorke, G. Biasiol, L. Sorba
cond-mat.mes-hall