Micropatterned Electrostatic Traps for Indirect Excitons in Coupled GaAs Quantum Wells

TL;DR

This paper presents a novel electrostatic trapping method for indirect excitons in coupled GaAs quantum wells, utilizing a SiO2 perimeter structure and a top gate to create nearly harmonic potential wells with high confinement strength.

Contribution

It introduces a new electrostatic trap design for indirect excitons in coupled GaAs quantum wells, combining quantum Stark effect and local field enhancement for effective confinement.

Findings

Trapping potentials are nearly harmonic with high spring constants.

Electrostatic trap is based on SiO2 perimeter and top gate structure.

Trap mechanism explained by Stark effect and field enhancement.

Abstract

We demonstrate an electrostatic trap for indirect excitons in a field-effect structure based on coupled GaAs quantum wells. Within the plane of a double quantum well indirect excitons are trapped at the perimeter of a SiO2 area sandwiched between the surface of the GaAs heterostructure and a semitransparent metallic top gate. The trapping mechanism is well explained by a combination of the quantum confined Stark effect and local field enhancement. We find the one-dimensional trapping potentials in the quantum well plane to be nearly harmonic with high spring constants exceeding 10 keV/cm^2.