Thermal Conductance of Ballistic Point Contacts

TL;DR

This paper investigates the thermal conductance of nanoscale ballistic point contacts in air-gap heterostructures, demonstrating significantly reduced heat transfer due to their small size and validating a Boltzmann transport model.

Contribution

It provides experimental measurements and a theoretical model for thermal conductance in ballistic nanostructures, highlighting their potential for thermal management.

Findings

Thermal conductance is several orders of magnitude lower than bulk materials.

Measurements agree quantitatively with Boltzmann transport equation-based model.

Ballistic point contacts effectively reduce heat transfer at nanoscale.

Abstract

We study the thermal conductance of ballistic point contacts. These contacts are realized as few nanometer long pillars in so called air-gap heterostructures (AGHs). The pillar length being much smaller that the mean free path of the phonons up to room temperature. Due to the small dimension and the low density of the pillars the thermal conductance of the AGHs is several orders of magnitude reduced in comparison to bulk structures. The measurement results are in quantitative agreement with a simple model that based on the Boltzmann transport equation.