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The demonstration of isotropic polarization response from semiconductor quantum dots (QDs) is a crucial step towards the design of several optoelectronic technologies. Among many parameters that impact the degree of polarization (DOP) of a…

Mesoscale and Nanoscale Physics · Physics 2012-10-09 Muhammad Usman

The design of some optical devices such as semiconductor optical amplifiers for telecommunication applications requires polarization-insensitive optical emission at the long wavelengths (1300-1550 nm). Self-assembled InAs/GaAs quantum dots…

Materials Science · Physics 2015-05-20 Muhammad Usman , Susannah Heck , Edmund Clarke , Peter Spencer , Hoon Ryu , Ray Murray , Gerhard Klimeck

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

III-V growth and surface conditions strongly influence the physical structure and resulting optical properties of self-assembled quantum dots (QDs). Beyond the design of a desired active optical wavelength, the polarization response of QDs…

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

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…

Mesoscale and Nanoscale Physics · Physics 2016-12-13 P. Klenovsky , D. Hemzal , P. Steindl , M. Zikova , V. Krapek , J. Humlicek

We present a comprehensive investigation of the polarization properties of non-polar a-plane InGaN quantum dots (QDs) and their origin with statistically significant experimental data and rigorous k.p modelling. The unbiased selection and…

We demonstrate a coherent quantum measurement for the determination of the degree of polarization (DOP). This method allows to measure the DOP in the presence of fast polarization state fluctuations, difficult to achieve with the typically…

Quantum Physics · Physics 2009-11-10 M. Legre , M. Wegmuller , N. Gisin

Tailoring electronic and optical properties of self-assembled InAs quantum dots (QDs) is a critical limit for the design of several QD-based optoelectronic devices operating in the telecom frequency range. We describe how a fine control of…

Mesoscale and Nanoscale Physics · Physics 2015-06-18 Vittorianna Tasco , Muhammad Usman , Milena De Giorgi , Adriana Passaseo

A model for realistic InAs quantum dot composition profile is proposed and analyzed, consisting of a double region scheme with an In-rich internal core and an In-poor external shell, in order to mimic the atomic scale phenomena such as…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Vittorianna Tasco , Muhammad Usman , Maria Teresa Todaro , Milena De Giorgi , Adriana Passaseo

Atomistic electronic structure calculations are performed to study the coherent inter-dot couplings of the electronic states in a single InGaAs quantum dot molecule. The experimentally observed excitonic spectrum [12] is quantitatively…

Mesoscale and Nanoscale Physics · Physics 2013-08-01 Muhammad Usman , Yui-Hong Matthias Tan , Hoon Ryu , Shaikh S. Ahmed , Hubert Krenner , Timothy B. Boykin , Gerhard Klimeck

The authors report that anisotropic confining potentials in laterally-coupled semiconductor quantum dots (QDs) have large impacts in optical transitions and energies of inter-shell collective electronic excitations. The observed…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Achintya Singha , Vittorio Pellegrini , Sokratis Kalliakos , Biswajit Karmakar , Aron Pinczuk , Loren N. Pfeiffer , Ken W. West

The optical response of (InGa)(AsSb)/GaAs quantum dots (QDs) grown on GaP (001) substrates is studied by means of excitation and temperature-dependent photoluminescence (PL), and it is related to their complex electronic structure. Such QDs…

Mesoscale and Nanoscale Physics · Physics 2019-11-13 Petr Steindl , Elisa Maddalena Sala , Benito Alén , David Fuertes Marrón , Dieter Bimberg , Petr Klenovský

In this paper, we address the problem of luminescence polarization in the case of nanostructures characterized by an in-plane shape asymmetry. We develop a simple semi-qualitative model revealing the mechanism that accounts for the…

Mesoscale and Nanoscale Physics · Physics 2012-01-20 Piotr Kaczmarkiewicz , Anna Musiał , Grzegorz Sęk , Paweł Podemski , Paweł Machnikowski , Jan Misiewicz

The full time-dependent four-wave mixing polarization in quantum dots is microscopically calculated, taking into account acoustic phonon-assisted transitions between different exciton states of the dot. It is shown that quite different…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 E. A. Muljarov , R. Zimmermann

We present a comprehensive study of quantum dot (QD) coupling to various phononic modes in a phononic waveguide, combining multiband kp and configuration-interaction (CI) QD state simulations with finite-element waveguide mode modeling. We…

Mesoscale and Nanoscale Physics · Physics 2026-01-21 Jakub Rosiński , Michał Gawełczyk , Matthias Weiß , Hubert J. Krenner , Paweł Machnikowski

We present an experimental and theoretical study of the polarized photoluminescence spectrum of single semiconductor quantum dots in various charge states. We compare our high resolution polarization sensitive spectral measurements with a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 E. Poem , J. Shemesh , I. Marderfeld , D. Galushko , N. Akopian , D. Gershoni , B. D. Gerardot , A. Badolato , P. M. Petroff

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

A detailed theoretical study of the optical absorption in self-assembled quantum dots is presented in this paper. A rigorous atomistic strain model as well as a sophisticated electronic band structure model are used to ensure accurate…

InN quantum dots (QDs) are considered to be promising nanostructures for different device applications. For any hexagonal AB stacking semiconductor system, polarity is an important feature which affects the electronic properties. Therefore,…

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