Interplay between Aharonov-Bohm interference and parity selective tunneling in zigzag graphene nanoribbon rings

TL;DR

This paper investigates how magnetic fields influence quantum interference and parity-based tunneling in zigzag graphene nanoribbon rings, revealing effects like giant magnetoresistance and negative differential conductance.

Contribution

It demonstrates that magnetic fields can reverse parity symmetry in graphene nanoribbons, modulating transport properties via Aharonov-Bohm interference, a novel insight into graphene mesoscopic systems.

Findings

AB oscillations with -phase shift between different parity states

Giant positive and negative magnetoresistance observed

Strong negative differential conductance achieved

Abstract

We report a numerical study on Aharonov-Bohm (AB) effect and parity selective tunneling in pn junctions based on zigzag graphene nanoribbon rings. We find that when applying a magnetic field to the ring, the AB interference can reverse the parity symmetry of incoming waves and hence can strongly modulate the parity selective transmission through the system. Therefore, the transmission between two states of different parity exhibits the AB oscillations with a \pi-phase shift, compared to the case of states of same parity. On this basis, it is shown that interesting effects such as giant (both positive and negative) magnetoresistance and strong negative differential conductance can be achieved in this structure. Our study thus presents a new property of the AB interference, which could be helpful to further understand the transport properties of graphene mesoscopic-systems.