A new relation between the hot electron power loss and acoustic phonon limited mobility in Bloch-Gr\"uneisen regime

TL;DR

This paper derives a simple, temperature- and concentration-independent relation between electron power loss and mobility limited by acoustic phonons in the Bloch-Gr"uneisen regime, applicable to 2D and 3D systems like GaAs and graphene.

Contribution

It introduces a novel relation linking power loss and mobility in the BG regime, enabling indirect mobility measurement from power loss data.

Findings

Derived a universal relation F(T)μ_p = η e v_s^2 independent of temperature and concentration.

Applied the relation to GaAs and graphene to estimate mobility from power loss measurements.

Proposed using F(T) measurements as a tool to determine low-temperature mobility affected by disorder.

Abstract

Expressions for the electron power loss F(T) and mobility {\mu}_p due to acoustic phonon scattering are given in the Bloch-Gr\"uneisen (BG) regime for three- and two- dimensional electron gas in semiconductors and Dirac-fermions. We obtain a simple relation F(T) {\mu}_p = {\eta}ev_s^2, where {\eta} (~1) is a constant, e is the electron charge and v_s is acoustic phonon velocity. It is found to be independent of temperature and electron concentration. This relation is applied to GaAs heterojucntions and graphene, to obtain {\mu}_p from the measured F(T). We propose that, using this relation, the measurements of F(T), in BG regime, which depends exclusively upon acoustic phonons coupling, could serve as a tool to determine the low temperature {\mu}_p, which is otherwise difficult to measure due to the contributions from disorders