R-matrix theory for nanoscale phonon thermal transport across devices and interfaces

TL;DR

This paper introduces an efficient R-matrix approach for calculating phonon scattering in nanoscale systems, requiring only the normal modes of the scattering region, demonstrated on atomic chains and graphene nanoribbons.

Contribution

The work adapts R-matrix theory for phonon transport, enabling simple and efficient calculations based solely on normal modes, applicable to various nanoscale systems.

Findings

R-matrix method accurately predicts phonon scattering.

Impurities significantly affect thermal transport.

Method validated on atomic chain and graphene nanoribbon.

Abstract

We have adapted R-matrix theory to calculate phonon scattering across systems of molecular to mesoscopic scale. The key novelty of this work is that the only required information about the scattering region are its normal modes, which are evaluated only once for a system. Thus, R-matrix theory is a computationally efficient and simple approach to calculate phonon scattering in larger systems. To validate and to demonstrate the applicability of the theory, we apply it to two systems: a one dimensional chain of atoms and a graphene nanoribbon. In both cases, we discuss the effect of mass impurities on thermal transport.