AC voltage effects on indirect excitons in a coupled quantum-well pair

TL;DR

This paper numerically investigates how AC voltage influences indirect excitons in coupled quantum wells, revealing potential for creating excitonic traps and generating terahertz radiation.

Contribution

It introduces a nonlinear dynamical model of excitonic wave packets under time-dependent electric fields in coupled quantum wells.

Findings

Resonant conditions are modified by the reaction field.

Possibility of electrostatic trapping of indirect excitons at high frequencies.

Potential emergence of terahertz radiation from excitonic traps.

Abstract

The objective of this work is to numerically integrate in space and time the effective-mass Schrodinger equation for an excitonic wave packet in a coupled quantum-well system under a time-dependent electric field. Taking as a starting point a time-dependent Hartree potential, we derive the nonlinear dynamical evolution of the excitonic wave function. We found that the system resonant condition can be modified owing to the reaction field generated by a charge dynamically trapped in the quantum-well pair. As a result, this study raises a broader question: is it possible to create an electrostatic trap for indirect excitons at high ac frequencies? We conclude there is a possibility of having another kind of terahertz electromagnetic radiation emerging from an excitonic trap.