Quantum Manifestations of Graphene Edge Stress and Edge Instability: A First-Principles Study

TL;DR

This study uses first-principles calculations to reveal quantum effects in graphene edge stresses, showing oscillations and reductions due to spin polarization, which influence edge stability and are not captured by classical models.

Contribution

It uncovers quantum manifestations of edge stress in graphene, including oscillations and spin effects, and explores mechanisms for stabilizing edge structures.

Findings

Armchair edge stress oscillates with nanoribbon width.

Zigzag edge stress is reduced by spin polarization.

Edge stabilization can be achieved through H adsorption or Stone-Wales reconstruction.

Abstract

We have performed first-principles calculations of graphene edge stresses, which display two interesting quantum manifestations absent from the classical interpretation: the armchair edge stress oscillates with a nanoribbon width, and the zigzag edge stress is noticeably reduced by spin polarization. Such quantum stress effects in turn manifest in mechanical edge twisting and warping instability, showing features not captured by empirical potentials or continuum theory. Edge adsorption of H and Stone-Wales reconstruction are shown to provide alternative mechanisms in relieving the edge compression and hence to stabilize the planar edge structure.