The effect of duty cycle on electron transmission through a graphene electrostatic barrier

TL;DR

This paper theoretically explores how duty cycle modulation of a rectangular electrostatic barrier affects electron transmission and Fano resonances in graphene, revealing new control mechanisms for quantum interference in nanostructures.

Contribution

It introduces the first analysis of duty cycle effects on quantum interference and Fano resonances in graphene nanostructures under rectangular driving potentials.

Findings

Duty cycle significantly influences electron transmission and Fano resonance characteristics.

Rectangular drive modulates the barrier transparency and resonance features.

The study provides insights for designing graphene-based sensors and modulators.

Abstract

We investigated theoretically the transmission properties of Dirac Fermions tunneling through a periodically (sinusoidal and rectangular) driven electrostatic barrier in Monolayer graphene. For the time harmonic potential with moderate to high alpha (=amplitude/frequency) the central Floquet band is found to be almost cloaked for the Klein transmitted electron in contrast to electron at higher grazing incidences. As a time periodic drive, we mainly focused on the use of rectangular wave electric signal to modulate the transparency of the barrier. It is noted that the asymmetric Fano resonance, a characteristic feature of photon assisted tunneling, is more likely to occur for rectangular drive in contrast to the harmonic one. The height of the modulating potential is particularly responsible for the dressing effect of the barrier. The position and nature of the FR can be tailored by changing the height and frequency of the rectangular drive. Moreover, the duty cycle of the driving potential turns out to be an important controlling parameter for the transmission process. Thus, the rectangular modulation plays an important role for the occurrence and detection of the Fano resonances which is vital for the use of graphene nanostructure in the field of detectors, sensors, modulators etc. The present findings attempt for the first time, to realize the effect of duty cycle on the quantum interference in semiconductor nanostructures.