Polarization anisotropy of the emission from type-II quantum dots

P Klenovský,M Zíková,V Křápek,D Hemzal,P Steindl,J Humlíček

doi:10.1103/physrevb.92.241302

Abstract

We study the polarization response of the emission from type-II GaAsSb capped InAs quantum dots. The theoretical prediction based on the calculations of the overlap integrals of the single-particle states obtained in the k.p framework is given. This is verified experimentally by polarization resolved photoluminescence measurements on samples with the type-II confinement. We show that the polarization anisotropy might be utilized to find the vertical position of the hole wavefunction and its orientation with respect to crystallographic axes of the sample. A proposition for usage in the information technology as a room temperature photonic gate operating at the communication wavelengths as well as a simple model to estimate the energy of fine-structure splitting for type-II GaAsSb capped InAs QDs are given.

Highlights

RAPID COMMUNICATIONSThe theoretical prediction based on the calculations of the overlap integrals of the single-particle states obtained in the k · p framework is given
The ground state wave function of holes in type-II InAs quantum dots (QDs) with a GaAs1−ySby capping layer (CL) resides outside of the dot volume and in general has the form of two mutually perpendicular pairs of segments [1,2]
We show that the polarization anisotropy might be utilized to find the vertical position of the hole wave function and its orientation with respect to crystallographic axes of the sample

Summary

RAPID COMMUNICATIONS

The theoretical prediction based on the calculations of the overlap integrals of the single-particle states obtained in the k · p framework is given This is verified experimentally by polarization resolved photoluminescence measurements on samples with the type-II confinement. The pair oriented along the [110] crystallographic direction is positioned close to the QD base, while the other, oriented along [1,2,3,4,5,6,7,8,9,10], is located above the dot [1,2,3,4,5] Both the vertical position and the orientation of the hole wave function have been recently discussed in the literature [3,4,5,6,7,8]. For more details see Refs. [10,11,12]

Results

Published by the American Physical Society

GaAsSb capped InAs QDs where the maximum of probability

Conclusions