Quantum Blockades and Loop Currents in Graphene with Topological Defects

TL;DR

This paper explores how topological defects in graphene induce quantum blockades and loop currents, revealing a new method to generate magnetic moments via electric fields for potential applications in carbon electronics.

Contribution

It demonstrates the emergence of quantum blockades and chiral loop currents in graphene caused by topological defects, a novel phenomenon not previously reported.

Findings

Longitudinal conductance vanishes at specific Fermi energies.

Loop orbital electric currents with chirality are induced by defects.

External electric fields can generate magnetic moments in graphene.

Abstract

We investigate the effect of topological defects on the transport properties of a narrow ballistic ribbon of graphene with zigzag edges. Our results show that the longitudinal conductance vanishes at several discrete Fermi energies where the system develops loop orbital electric currents with certain chirality. The chirality depends on the direction of the applied bias voltage and the sign of the local curvature created by the topological defects. This novel quantum blockade phenomenon provides a new way to generate a magnetic moment by an external electric field, which can prove useful in carbon electronics.