Coherent edge mixing and interferometry in quantum Hall bilayers
  We discuss the implementation of a beam splitter for electron waves in a quantum Hall bilayer. Our architecture exploits inter-layer tunneling to mix edge states belonging to different layers. We discuss the basic working principle of the proposed coherent edge mixer, possible interferometric implementations based on existing semiconductor-heterojunction technologies, and advantages with respect to canonical quantum Hall interferometers based on quantum point contacts. 
Stefano Roddaro, Luca Chirolli, Fabio Taddei, Marco Polini and   Vittorio Giovannetti
cond-mat.mes-hall quant-ph