Electronic and magnetic properties of twisted graphene nanoribbon and M\"obius strips: first-principles calculations

TL;DR

This study uses first-principles calculations to explore how twisting affects the electronic and magnetic properties of graphene nanoribbons and Möbius strips, revealing stability, energy, and magnetic behavior changes.

Contribution

It provides a systematic first-principles analysis of twisted graphene nanoribbons and Möbius strips, highlighting their stability, electronic, and magnetic properties as functions of twisting.

Findings

Atomic bonding energy decreases quadratically with twist angle.

HOMO-LUMO gap varies sinusoidally with twist angle.

ZGNRS and GMS exhibit antiferromagnetic ground states during twisting.

Abstract

The geometrical, electronic, and magnetic properties of twisted zigzag-edged graphene nanoribbons (ZGNRs) and novel graphene M\"obius strips (GMS) are systematically investigated using first-principles density functional calculations. The structures of ZGNRs and GMS are optimized, and their stabilities are examined. The molecular energy levels and the spin polarized density of states are calculated. It is found that for twisted ZGNRs, the atomic bonding energy decreases quadratically with the increase of the twisted angle, and the HOMO-LUMO gap are varying in a sine-like behavior with the twisted angle. The calculated spin densities reveal that the ZGNRs and GMS have antiferromagnetic ground states, which persist during the twisting. The spin flips on the zigzag edges of GMS are observed at some positions.