Extremely weak sub-kelvin electron-phonon coupling in InAs On Insulator

TL;DR

This paper introduces InAs on insulator as a promising platform for subKelvin caloritronic devices, highlighting its extremely weak electron-phonon coupling which surpasses metallic counterparts, enabling more efficient thermal management at ultra-low temperatures.

Contribution

The study demonstrates that InAs on insulator exhibits electron-phonon coupling constants up to two orders of magnitude lower than metallic devices, advancing caloritronic technology.

Findings

Significantly reduced e-ph coupling in InAsOI compared to metals

Potential for improved caloritronic device efficiency at subKelvin temperatures

InAsOI as an ideal platform for low-power thermal management

Abstract

We are proposing, as an ideal candidate for caloritronic devices operating at subKelvin temperatures, a hybrid superconductor-semiconductor platform named InAs on insulator (InAsOI). This heterostructure is made by doped InAs grown on an insulating buffer of InAlAs on a GaAs substrate. Caloritronic devices aim to heat or cool electrons out of equilibrium with respect to the phonon degree of freedom. However, their performances are usually limited by the strength of the electron-phonon (e-ph) coupling and the associated power loss. Our work discusses the advantages of the InAsOI platform, which are based on the significantly low e-ph coupling measured compared to all-metallic state-of-the-art caloritronic devices. Our structure demonstrates values of the e-ph coupling constant up to two orders of magnitude smaller than typical values in metallic structures.