We consider the violation of the Leggett-Garg inequality in electronic Mach-Zehnder inteferometers. This setup has two distinct advantages over earlier quantum-transport proposals: Firstly, the required correlation functions can be obtained without time-resolved measurements. Secondly, the geometry of an interferometer allows one to construct the correlation functions from ideal negative measurements, which addresses the noninvasiveness requirement of the Leggett-Garg inequality. We discuss two concrete realizations of these ideas: the first in quantum Hall edge-channels, the second in a double quantum dot interferometer.

• Received 9 October 2012

DOI:https://doi.org/10.1103/PhysRevB.86.235447