Two beam Aharonov–Bohm interference in the integer quantum Hall regime

We study an electronic Mach–Zehnder interferometer employing the edge channels of a two-dimensional electron gas (2DEG) in the quantum Hall regime and quantum point contacts (QPC) as beam splitters. The linear conductance of the QPC as a function of gate voltage shows resonances superimposed on quantized conductance steps. It was found that the visibility depends strongly on magnetic field and is highest near a filling factor of 1.5 in the interferometer arm.