Effect of second order piezoelectricity on excitonic structure of stress-tuned InGaAs/GaAs quantum dots

TL;DR

This study investigates how second-order piezoelectric effects influence the excitonic properties of stress-tuned InGaAs/GaAs quantum dots, highlighting the importance of nonlinear piezoelectricity in quantum dot behavior.

Contribution

It provides a detailed analysis of second-order piezoelectricity effects on quantum dot properties and offers a simple relation to estimate stress-induced dipole moment changes.

Findings

Second-order piezoelectricity significantly affects exciton energy and dipole moments.

A simple relation estimates the influence of anisotropic stress on quantum dots.

Nonlinear piezoelectric effects are crucial for accurate quantum dot modeling.

Abstract

We study the effects of the nonlinear piezoelectricity and the In distribution on the exciton energy, the electron-hole electric dipole moment, and the fine-structure splitting in stress-tunable InGaAs/GaAs quantum dots integrated onto a piezoelectric actuator. In particular, we investigate in detail the contributions of various elements of the expansion of the electrical polarization in terms of externally induced elastic strain on the latter two important quantum dot properties. Based on the comparison of the effects of first- and second-order piezoelectricity we provide a simple relation to estimate the influence of applied anisotropic stress on the quantum dot dipole moment for quantum dots significantly lattice mismatched to the host crystal.