Some electronic and optical properties of self-assembled quantum dots: asymmetries in a lens domain

TL;DR

This paper investigates the intrinsic asymmetries in self-assembled quantum dots with lens domains, analyzing their optical and electronic properties under external electric fields to understand how shape and field influence their behavior.

Contribution

It provides a detailed analysis of asymmetry effects in lens-shaped quantum dots and how external electric fields can be used to tune their electronic and optical properties.

Findings

Asymmetry effects decrease with flatter lens domains.

Significant Stark shifts depend on the lens shape and field direction.

Optical properties like dielectric constant and electroabsorption reveal energy spectrum signatures.

Abstract

The self-assembled quantum dot with lens domain has rotational symmetry but it is intrinsically asymmetric when the electron moves perpendicularly to its circular base, {\it i. e.} along the rotational axis. To characterize this asymmetry, an external electric field is applied along the positive or negative direction of the rotational axis. We report the different Stark shifts appearing in the spectra as a function of the field intensity for different lens domains. It is shown that for a flat lens domain the asymmetry effects decrease, but even for very flat lenses they can not be approximated by a cylindrical domain. Finally, some optical properties such as the dielectric constant and electroabsorption are studied. Signatures of the energy spectrum reveal in these quantities. The importance of considering the proper lens domain as long as the magnitude and direction field to tune a specific level transition is stressed.