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We investigate the properties of electronic states and optical transitions in hexagonal GaAs quantum dots within AlGaAs nanowires. Such dots are particularly interesting due to their high degree of symmetry. A streamlined postsymmetrization…

Mesoscale and Nanoscale Physics · Physics 2015-11-18 Guro K. Svendsen , Johannes Skaar , Helge Weman , Marc-André Dupertuis

A study of previously overlooked structural and optical properties of InGaAs heterostructures grown on (111)B oriented GaAs substrates patterned with inverted 7.5 um pitch pyramidal recesses is presented. First, the composition of the…

This work presents an analysis of the electronic and optical properties of InAs/GaAs columnar quantum dots (QDs) by performing multi-million-atom tight-binding simulations. The plots of the polarisation-dependent ground state optical…

Mesoscale and Nanoscale Physics · Physics 2020-06-30 Muhammad Usman

A sequence of photoluminescence spectroscopy based methods are used to rigorously identify and study all the main spectral features (more than thirty emission lines) of site controlled InGaAs/AlGaAs quantum dots (QDs) grown along [111]B in…

By combining band gap engineering with the self-organized growth of quantum dots, we present a scheme of adjusting the mid-infrared absorption properties to desired energy transitions in quantum dot based photodetectors. Embedding the self…

Other Condensed Matter · Physics 2013-05-29 F. F. Schrey , L. Rebohle , T. Mueller , G. Strasser , K. Unterrainer , D. P. Nguyen , N. Regnault , R. Ferreira , G. Bastard

We use an $sp^3d^5s^* $ tight-binding model to investigate the electronic and optical properties of realistic site-controlled (111)-oriented InGaAs/GaAs quantum dots. Special attention is paid to the impact of random alloy fluctuations on…

Materials Science · Physics 2016-09-16 R. Benchamekh , S. Schulz , E. P. O'Reilly

Dilute arrays of GaAs/AlGaAs modulation-doped quantum dots (QDs) fabricated by electron-beam lithography and low impact reactive-ion etching exhibit highly homogeneous luminescence. Single quantum dots display spectral emission with peak…

The optical properties of excitons confined in initially-unstrained GaAs/AlGaAs quantum dots are studied as a function of a variable quasi-uniaxial stress. To allow the validation of state-of-the-art computational tools for describing the…

Strain-free GaAs/AlGaAs semiconductor quantum dots (QDs) grown by droplet etching and nanohole infilling (DENI) are highly promising candidates for the on-demand generation of indistinguishable and entangled photon sources. The…

Site-controlled quantum dots formed during the deposition of (Al)GaAs layers by metalorganic vapor-phase epitaxy on GaAs(111)B substrates patterned with inverted pyramids result in geometric and compositional self-ordering along the…

Materials Science · Physics 2013-06-11 V. Dimastrodonato , E. Pelucchi , P. A. Zestanakis , D. D. Vvedensky

In this work, we present and evaluate a (111)-rotated eight-band $\mathbf{k}\cdot\mathbf{p}$ Hamiltonian for the zinc-blende crystal lattice to investigate the electronic properties of site-controlled InGaAs/GaAs quantum dots grown along…

Mesoscale and Nanoscale Physics · Physics 2013-11-12 O. Marquardt , E. P. O'Reilly , S. Schulz

Quantum dot lattices (QDLs) have the potential to allow for the tailoring of optical, magnetic and electronic properties of a user-defined artificial solid. We use a dual gated device structure to controllably tune the potential landscape…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Srijit Goswami , M. A. Aamir , Christoph Siegert , Michael Pepper , Ian Farrer , David A. Ritchie , Arindam Ghosh

We report on a atomistic theory of electronic structure and optical properties of a single InAs quantum dot grown on InP patterned substrate. The spatial positioning of individual dots using InP nano-templates results in a quantum dot…

Materials Science · Physics 2009-11-11 Weidong Sheng , Pawel Hawrylak

We show that fully self-assembled optically-active quantum dots (QDs) embedded in MBE-grown GaAs/AlGaAs core-shell nanowires (NWs) are coupled to the NW mechanical motion. Oscillations of the NW modulate the QD emission energy in a broad…

Mesoscale and Nanoscale Physics · Physics 2014-08-22 M. Montinaro , G. Wüst , M. Munsch , Y. Fontana , E. Russo-Averchi , M. Heiss , A. Fontcuberta i Morral , R. J. Warburton , M. Poggio

The structural and electronic properties of cubic GaN are studied within the local density approximation by the full-potential linear muffin-tin orbitals method. The Ga $3d$ electrons are treated as band states, and no shape approximation…

Condensed Matter · Physics 2009-10-22 Vincenzo Fiorentini , Michael Methfessel , Matthias Scheffler

We study theoretically the electronic properties of $c$-plane GaN/AlN quantum dots (QDs) with focus on their potential as sources of single polarized photons for future quantum communication systems. Within the framework of eight-band k.p…

Materials Science · Physics 2008-10-23 M. Winkelnkemper , R. Seguin , S. Rodt , A. Hoffmann , D. Bimberg

Optical control of the lateral quantum confinement and number of electrons confined in nanofabricated GaAs/AlGaAs quantum dots is achieved by illumination with a weak laser beam that is absorbed in the AlGaAs barrier. Precise tuning of…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Sokratis Kalliakos , Vittorio Pellegrini , Cesar Pascual Garcia , Aron Pinczuk , Loren N. Pfeiffer , Ken. W. West

Multi-million atom simulations are performed to study stacking-angle ($\theta$) dependent strain profiles, electronic structure, and polarization-resolved optical modes from [110]-tilted quantum dot stacks (QDSs). Our calculations reveal…

Mesoscale and Nanoscale Physics · Physics 2014-03-18 Muhammad Usman

Free standing beams containing a two-dimensional electron system are shaped from a GaAs/AlGaAs heterostructure. Quantum point contacts and (double) quantum dots are laterally defined using metal top gates. We investigate the electronic…

Mesoscale and Nanoscale Physics · Physics 2010-06-17 C Rossler , M Bichler , D Schuh , W Wegscheider , S Ludwig

In this chapter quantum many body theoretical methods have been used to study properties of GaAs - and InAs - based, small semiconductor compound quantum dots (QDs) containing manganese or vanadium atoms. Interest to such systems has grown…

Mesoscale and Nanoscale Physics · Physics 2012-09-25 Liudmila A. Pozhar
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