Type II InAs/GaAsSb Quantum Dots: Highly Tunable Exciton Geometry and Topology

TL;DR

This paper explores how external electric fields can control the geometry and topology of excitons in InAs/GaAsSb quantum dots, revealing tunable dipole moments and a transition from quantum dot to ring-like hole wavefunctions.

Contribution

It demonstrates the ability to manipulate exciton properties and topology in type II quantum dots using external bias, a novel approach for quantum control.

Findings

Highly tunable exciton dipole moments.

Decoupled exciton recombination and ionization dynamics.

Predicted transition of hole wavefunction topology from quantum dot to ring.

Abstract

External control over the electron and hole wavefunctions geometry and topology is investigated in a p-i-n diode embedding a dot-in-a-well InAs/GaAsSb quantum structure with type II band alignment. We find highly tunable exciton dipole moments and largely decoupled exciton recombination and ionization dynamics. We also predicted a bias regime where the hole wavefunction topology changes continuously from quantum dot-like to quantum ring-like as a function of the external bias. All these properties have great potential in advanced electro-optical applications and in the investigation of fundamental spin-orbit phenomena.