Helicoidal Graphene Nanoribbons: Chiraltronics

TL;DR

This paper investigates the quantum effects in helicoidal graphene nanoribbons, revealing a twist-induced electric field that separates chiral iso-spin states and suggests potential for THz radiation applications.

Contribution

It introduces a novel geometric model for helicoidal graphene nanoribbons and predicts a mechanism for chiral separation based on geometry-induced quantum potentials.

Findings

Twist acts as an effective transverse electric field.

Chiral iso-spin states are separated on opposing rims.

Potential for microwave and THz radiation interactions.

Abstract

We present a calculation of the effective geometry-induced quantum potential for the carriers in graphene shaped as a helicoidal nanoribbon. In this geometry the twist of the nanoribbon plays the role of an effective transverse electric field in graphene and this is reminiscent of the Hall effect. However, this effective electric field has a different sign for the two iso-spin states and translates into a mechanism to separate the two chiral species on the opposing rims of the nanoribbon. Iso-spin transitions are expected with the emission or absorption of microwave radiation which could be adjusted to be in the THz region.