Fully Tunable Fano Resonances in Chiral Electronic Transport

Abstract

Fano resonance arises from interference between a direct path and a resonant path. Predictions and observations of Fano profiles of conductance have been reported yet only in nonchiral electron transport. We propose an electronic Mach-Zehnder-Fano interferometer(\textcolor{blue}{MZFI}) that integrates a quantum dot to an electronic Mach-Zehnder interferometer and investigate various transport spectra of this type of device. Electron motion in the device is chiral and backscattering is absent, enabling the transmission, linear conductance and differential spectra such as differential conductance, differential shot noise and differential Fano factor to possess perfect Fano profiles that can be fully tuned by an external magnetic flux. For a symmetric interferometer of(two arms with the same length, even the current and shot noise demonstrate fully tunable resonances and are bestowed different hallmarks unique to Fano resonances. All the transport spectra display the same evolution pattern in an evolution cycle, which along with the profiles are robust against variation of the parameters defining the device.