English
Related papers

Related papers: Electronic and optical properties in non-uniformly…

200 papers

We theoretically study the optical properties and the electronic structure of highly elongated quantum dots (quantum dashes) and show how geometrical fluctuations affect the excitonic spec- trum of the system. The dependence of the…

Mesoscale and Nanoscale Physics · Physics 2023-07-19 Piotr Kaczmarkiewicz , Paweł Machnikowski , Tilmann Kuhn

We study the optical properties of highly anisotropic quantum dot structures (quantum dashes) characterized by the presence of two trapping centers located along the structure. Such a system can exhibit some of the properties characteristic…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Piotr Kaczmarkiewicz , Paweł Machnikowski , Tilmann Kuhn

We study experimentally and theoretically polarization-dependent luminescence from an ensemble of quantum-dot-like nanostructures with a very large in-plane shape anisotropy (quantum dashes). We show that the measured degree of linear…

Mesoscale and Nanoscale Physics · Physics 2012-01-20 A. Musiał , P. Kaczmarkiewicz , G. Sęk , P. Podemski , P. Machnikowski , J. Misiewicz , S. Hein , S. Höfling , A. Forchel

Excitons confined to flat semiconductor quantum dots with elliptical cross section are considered as we study geometrical effects on exciton binding energy, electron-hole separation, and the resulting linear optical properties. We use…

Condensed Matter · Physics 2009-10-28 Jakyoung Song , Sergio E. Ulloa

A transition from a cylindrical quantum dot to a highly elongated quantum dash is theoretically studied here with an atomistic approach combining empirical tight binding for single particle states and configuration interaction method for…

Mesoscale and Nanoscale Physics · Physics 2019-05-08 Michał Zieliński

The spectral properties of one exciton trapped in a self-assembled multi-layered quantum dot is obtained using a high precision variational numerical method. The exciton Hamiltonian includes the effect of the polarization charges, induced…

Quantum Physics · Physics 2014-12-24 Mariano Garagiola , Omar Osenda

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

Optical properties of large arrays of isolated quantum dots are discussed in order to interpret the existent photoluminescence data. The presented theory explains the large observed shift between the lowest emission and absorption energies…

Condensed Matter · Physics 2009-10-28 E. V. Tsiper

We present a theory of excitonic processes in gate controlled graphene quantum dots. The dependence of the energy gap on shape, size and edge for graphene quantum dots with up to a million atoms is predicted. Using a combination of…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 A. D. Guclu , P. Potasz , P. Hawrylak

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…

The electronic states of an electrostatically confined cylindrical graphene quantum dot and the electric transport through this device are studied theoretically within the continuum Dirac-equation approximation and compared with numerical…

Mesoscale and Nanoscale Physics · Physics 2011-08-12 G. Pal , W. Apel , L. Schweitzer

Electronic structure and transport characteristics of coupled CdS and ZnSe quantum dots are studied using density functional theory and non equilibrium Greens function method respectively. Our investigations show that in these novel coupled…

Mesoscale and Nanoscale Physics · Physics 2021-08-03 Simon Liebing , Torsten Hahn , Jens Kortus , Bidisa Das , Arup Chakraborty , Indra Dasgupta

Hereby, we present a comprehensive experimental and theoretical study of the electronic structure and optical properties of excitonic complexes in strain-engineered InGaAs/GaAs quantum dots (QDs) grown by metal-organic chemical vapour…

We present both experimental and theoretical results on the influence of a magnetic field on excitons in semiconductor quantum dots. We find a pronounced difference between the strong and weak confinement regimes. For weak confinement, the…

We investigate the effects of point charge defects on the single particle electronic structure, emission energies, fine structure splitting and oscillator strengths of excitonic transitions in strained In$_{0.6}$Ga$_{0.4}$As/GaAs and…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Ranber Singh , Gabriel Bester

We study the localization of dressed Dirac electrons in a cylindrical quantum dot (QD) formed on monolayer and bilayer graphene by spatially different potential profiles. Short lived excitonic states which are too broad to be resolved in…

Materials Science · Physics 2015-06-03 O. Roslyak , G. Gumbs , S. Mukamel

In this review, we discuss the electronic structure of finite quantal systems on the nanoscale. After a few general remarks on the many-particle physics of the harmonic oscillator -- likely being the most studied example for the many-body…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Manninen , S. M. Reimann

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

The study investigates and compares the impact of intense, non-diffractive, non-resonant structured laser beams with various intensity profiles on the properties of InAs/GaAs cylindrical quantum dot. The comparative study demon-strates that…

Mesoscale and Nanoscale Physics · Physics 2025-06-13 T. A. Sargsian , P. A. Mantashyan , D. B. Hayrapetyan

We report on the carrier dynamics in InGaN/GaN disk-in-a-wire quantum dots with precisely controlled location and structural parameters, including diameter, thickness and material composition. We measured the time-integrated and…

Mesoscale and Nanoscale Physics · Physics 2015-01-07 Lei Zhang , Tyler A. Hill , Chu-Hsiang Teng , Brandon Demory , Pei-Cheng Ku , Hui Deng
‹ Prev 1 2 3 10 Next ›