Current-driven collective dynamics of non-Hermitian edge vibrations in armchair graphene nanoribbons

We study non-Hermitian collective dynamics of spatially separated edge carbon dimer vibrations in armchair graphene nanoribbons, mediated by coherent and dissipative coupling to nonequilibrium electron transport. We show that the indirect coupling between two dimers depends crucially on gating and source-drain bias. In particular, we analyze the competition between two distinctly different energy transfer mechanism from nonequilibrium electrons to vibrations. One is the deterministic work done by nonconservative current-induced force, and the other is stochastic Joule heating. We find that the effect of the former can be effectively tuned electrically through gating and bias. Our work suggests that armchair graphene nanoribbons could serve as promising candidates in the experimental search for signatures of nonconservative current-induced forces in nanoconductors, which remains elusive despite intense theoretical study.

Automated summary

We investigate the non-Hermitian collective dynamics of spatially separated edge carbon dimer vibrations in armchair graphene nanoribbons, which are mediated by coherent and dissipative coupling to nonequilibrium electron transport. We demonstrate that the indirect coupling between two dimers crucially depends on gating and source-drain bias. In particular, we analyze the competition between two distinct energy transfer mechanisms from nonequilibrium electrons to vibrations, namely deterministic work done by nonconservative current-induced force and stochastic Joule heating. Our findings suggest that armchair graphene nanoribbons could be promising candidates for experimental exploration of nonconservative current-induced forces in nanoconductors.