Transmission eigenchannels for coherent phonon transport

TL;DR

This paper introduces a method to identify transmission eigenchannels for coherent phonon transport in nanoscale devices, combining Green's functions with ab initio calculations to analyze heat transfer at atomic scales.

Contribution

It presents a novel procedure to determine phonon transmission eigenchannels, applicable to realistic atomic-scale junctions, enhancing understanding of phonon heat transport.

Findings

Analyzed phonon eigenchannels in a gold atomic contact.

Identified destructive interference effects in specific molecular junctions.

Demonstrated the method's applicability to realistic nanoscale systems.

Abstract

We present a procedure to determine transmission eigenchannels for coherent phonon transport in nanoscale devices using the framework of nonequilibrium Green's functions. We illustrate our procedure by analyzing a one-dimensional chain, where all steps can be carried out analytically. More importantly, we show how the procedure can be combined with ab initio calculations to provide a better understanding of phonon heat transport in realistic atomic-scale junctions. In particular, we study the phonon eigenchannels in a gold metallic atomic-size contact and different single-molecule junctions based on molecules such as an alkane chain, C$_{60}$, and a brominated benzene-diamine, where in this latter case destructive phonon interference effects take place.