Semiconductor quantum dots with light-hole exciton ground state: fabrication and fine structure
Abstract
Quantum dots (QDs) can act as convenient hosts of two-level quantum szstems, such as single electron spins, hole spins or excitons (bound electron-hole pairs). Due to quantum confinement, the ground state of a single hole confined in a QD usually has dominant heavy-hole (HH) character. For this reason light-hole (LH) states have been largely neglected, despite the fact that may enable the realilzation of coherent photon-to-spin converters or allow for faster spin manipulation compared to HH states. In this work, we use tensile strains larger than 0.3% to switch the ground state of excitons confined in high quality GaAs/AlGaAs QDs from the conventional HH- to LH-type. The LH-exciton fine structure is characterized by two in-plane-polarized lines and, ~400 micro-eV above them, by an additional line with pronounced out-of-plane oscillator strength, consistent with theoretical predictions based on atomistic empirical pseudopotential calculations and a simple mesoscopic model.
Keywords
Cite
@article{arxiv.1208.6554,
title = {Semiconductor quantum dots with light-hole exciton ground state: fabrication and fine structure},
author = {Y. H. Huo and B. J. Witek and S. Kumar and R. Singh and E. Zallo and R. Grifone and D. Kriegner and R. Trotta and N. Akopian and J. Stangl and V. Zwiller and G. Bester and A. Rastelli and O. G. Schmidt},
journal= {arXiv preprint arXiv:1208.6554},
year = {2012}
}
Comments
16 pages, 4 figures