Surface acoustic wave controlled charge dynamics in a thin InGaAs quantum well

TL;DR

This study investigates how surface acoustic waves influence charge dynamics in a thin InGaAs quantum well, revealing a transition in modulation behavior and providing insights into carrier transport mechanisms.

Contribution

It presents the first experimental analysis of SAW-controlled charge dynamics in a thin quantum well, validated by numerical simulations for calibration.

Findings

Transition from one to two maxima in modulation with increasing acoustic power

Carrier mobilities limit electron-hole pair dissociation at low power

High power induces efficient acousto-electric carrier transport

Abstract

We experimentally study the optical emission of a thin quantum well and its dynamic modulation by a surface acoustic wave (SAW). We observe a characteristic transition of the modulation from one maximum to two maxima per SAW cycle as the acoustic power is increased which we find in good agreement with numer- ical calculations of the SAW controlled carrier dynamics. At low acoustic powers the carrier mobilites limit electron-hole pair dissociation, whereas at high power levels the induced electric fields give rise to efficient acousto-electric carrier transport. The direct comparison between the experimental data and the numerical simulations provide an absolute calibration of the local SAW phase.