LO-phonon emission rate of hot electrons from an on-demand single-electron source in a GaAs/AlGaAs heterostructure

TL;DR

This paper introduces a high-resolution measurement technique to determine LO-phonon emission rates of hot electrons in a GaAs/AlGaAs heterostructure, revealing a controllable scattering process suitable for scalable single-electron devices.

Contribution

It presents a novel time-of-flight and electron-energy spectroscopy method to measure phonon emission rates and demonstrates suppression of scattering via edge potential control.

Findings

Scattering length > 1 mm achieved

Main scattering involves intra-Landau-level transition

Method enables scalable single-electron device applications

Abstract

Using a recently-developed time-of-flight measurement technique with 1 ps time resolution and electron-energy spectroscopy, we developed a method to measure the longitudinal-optical-phonon emission rate of hot electrons travelling along a depleted edge of a quantum Hall bar. A comparison of the experimental results to a single-particle model implies that the main scattering mechanism involves a two-step process via intra-Landau-level transition. We show this scattering can be suppressed by controlling the edge potential profile, and a scattering length > 1 mm can be achieved, allowing the use of this system for scalable single-electron device applications.