Current-induced runaway vibrations in dehydrogenated graphene nanoribbons

TL;DR

This study investigates how electrical current induces vibrational instabilities in dehydrogenated graphene nanoribbons, revealing the role of nonconservative forces and potential for experimental testing.

Contribution

The paper introduces a semi-classical Langevin approach with DFT parameters to analyze current-induced atomic dynamics in dehydrogenated graphene nanoribbons, highlighting the effects of current-mediated forces.

Findings

Current can coherently couple dimer motions.

Nonconservative and pseudo-magnetic forces influence dynamics.

Nanoribbons can serve as testbeds for current-induced force effects.

Abstract

We employ a semi-classical Langevin approach to study current-induced atomic dynamics in a partially dehydrogenated armchair graphene nanoribbon. All parameters are obtained from density functional theory. The dehydrogenated carbon dimers behave as effective impurities, whose motion decouples from the rest of carbon atoms. The electrical current can couple the dimer motion in a coherent fashion. The coupling, which is mediated by nonconservative and pseudo-magnetic current-induced forces, change the atomic dynamics, and thereby show their signature in this simple system. We study the atomic dynamics and current-induced vibrational instabilities using a simplified eigen-mode analysis.Our study shows that the armchair nanoribbon serves as a possible testbed for probing the current-induced forces.