Fully tunable Fano resonances in chiral electronic transport

Abstract

Fano resonance is believed to arise when a direct path interferes with a resonant path. We demonstrate that this is not true for chiral electronic transmission without additional direct paths. To address the Fano effect in chiral electronic transport, we suggest an electronic Mach-Zehnder-Fano interferometer, which integrates a quantum dot into an electronic Mach-Zehnder interferometer. Due to the absence of backscattering in chiral electronic transport, Fano resonances can be fully adjusted by an external magnetic flux in the transmission, linear conductance, differential conductance, and differential shot noise of chiral electrons. Even the current and shot noise for a symmetric interferometer with two arms of the same length exhibit fully controllable resonances and distinct Fano characteristics. In particular, all the profiles in the various transport spectra follow the same evolution pattern in an evolution cycle that is resistant to changes in the device's defining parameters.