Phonon spectral density in a GaAs/AlGaAs double quantum dot

TL;DR

This paper investigates phonon emission in a GaAs/AlGaAs double quantum dot by analyzing electron tunneling rates, revealing interference effects in phonon spectral density through experimental measurements and fitting.

Contribution

It provides the first detailed measurement and analysis of phonon spectral density and interference effects in a GaAs/AlGaAs double quantum dot system.

Findings

Observation of oscillations in tunneling rates due to phonon interference

Fitting of transition rates reveals phonon spectral density features

Demonstration of phonon effects on electron tunneling in quantum dots

Abstract

We study phonon emission in a GaAs/AlGaAs double quantum dot by monitoring the tunneling of a single electron between the two dots. We prepare the system such that a known amount of energy is emitted in the transition process. The energy is converted into lattice vibrations and the resulting tunneling rate depends strongly on the phonon scattering and its effective phonon spectral density. We are able to fit the measured transition rates and see imprints of interference of phonons with themselves causing oscillations in the transition rates.