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相关论文: Asymmetry in self-assembled quantum dot-molecules …

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Most self-assembled quantum dot molecules are intrinsically asymmetric with inequivalent dots resulting from imperfect control of crystal growth. We have grown vertically-aligned pairs of InAs/GaAs quantum dots by molecular beam epitaxy,…

Molecular states in a SINGLE PAIR of strongly coupled self-assembled InAs quantum dots are investigated using a sub-micron sized single electron transistor containing just a few pairs of coupled InAs dots embedded in a GaAs matrix. We…

介观与纳米尺度物理 · 物理学 2007-05-23 T. Ota , M. Stopa , M. Rontani , T. Hatano , K. Yamada , S. Tarucha , H. Z. Song , Y. Nakata , T. Miyazawa , T. Ohshima , N. Yokoyama

Using single-particle pseudopotential and many-particle configuration interaction methods, we compare various physical quantities of (In,Ga)As/GaAs quantum dot molecules (QDMs) made of dissimilar dots (heteropolar QDMs) with QDMs made of…

材料科学 · 物理学 2015-06-25 Lixin He , Alex Zunger

In this work the intersubband electronic properties of two laterally coupled dome-shaped InAs/GaAs quantum dots were investigated. The envelope functions and eigenenergies were calculated as function of distance between the dots. The…

材料科学 · 物理学 2013-12-12 A. Khaledi-Nasab , M. Shahzadeh , H. Amouzegar , M. Sabaeian

We report on a combined photoluminescence imaging and atomic force microscopy study of single, isolated self-assembled InAs quantum dots (density <0.01 um^(-2) capped by a 95 nm GaAs layer, and emitting around 950 nm. By combining optical…

介观与纳米尺度物理 · 物理学 2017-07-27 Luca Sapienza , Jin Liu , Jin Dong Song , Stefan Falt , Werner Wegscheider , Antonio Badolato , Kartik Srinivasan

We observe the low-lying excitations of a molecular dimer formed by two electrons in a GaAs semiconductor quantum dot in which the number of confined electrons is tuned by optical illumination. By employing inelastic light scattering we…

介观与纳米尺度物理 · 物理学 2010-06-16 Achintya Singha , Vittorio Pellegrini , Aron Pinczuk , Loren N. Pfeiffer , Ken W. West , Massimo Rontani

We present results of correlated pseudopotential calculations of an exciton in a pair of vertically stacked InGaAs/GaAs dots. Competing effects of strain, geometry, and band mixing lead to many unexpected features missing in contemporary…

材料科学 · 物理学 2012-03-08 Gabriel Bester , J. Shumway , Alex Zunger

We have studied theoretically the type-II GaAsSb capped InAs quantum dots for two structures differing in the composition of the capping layer, being either (i) constant or (ii) with Sb accumulation above the apex of the dot. We have found…

介观与纳米尺度物理 · 物理学 2023-07-19 P. Klenovsky , V. Krapek , J. Humlicek

We discuss symmetry breaking in two-dimensional quantum dots resulting from strong interelectron repulsion relative to the zero-point kinetic energy associated with the confining potential. Such symmetry breaking leads to the emergence of…

介观与纳米尺度物理 · 物理学 2009-11-11 Constantine Yannouleas , Uzi Landman

We study the electronic and optical properties of laterally coupled InGaAs/GaAs quantum dot molecules under lateral electric field. We find that electrons perceive the double-dot structure as a compound single object, while the holes…

While electronic and spectroscopic properties of self-assembled In_{1-x}Ga_{x}As/GaAs dots depend on their shape, height and alloy compositions, these characteristics are often not known accurately from experiment. This creates a difficulty…

材料科学 · 物理学 2009-11-11 Gustavo A. Narvaez , Gabriel Bester , Alex Zunger

The optical spectrum of a quantum dot is typically dominated by the fundamental transition between the lowest-energy configurations. However, the radiative Auger process can result in additional red-shifted emission lines. The origin of…

Polarization-resolved single dot spectroscopy performed on (211)B InAs/GaAs quantum dots reveals that the fine structure splitting of the excitonic levels in these dots is much lower compared to the usual (100)-grown InAs dots.…

We investigate the dissociation of few-electron circular vertical semiconductor double quantum dot artificial molecules at 0 T as a function of interdot distance. Slight mismatch introduced in the fabrication of the artificial molecules…

凝聚态物理 · 物理学 2009-11-07 M. Pi , A. Emperador , M. Barranco , F. Garcias , K. Muraki , S. Tarucha , D. G. Austing

Vertically stacked and coupled InAs/GaAs self-assembled quantum dots (SADs) are predicted to exhibit a strong non-parabolic dependence of the interband transition energy on the electric field, which is not encountered in single SAD…

介观与纳米尺度物理 · 物理学 2009-11-07 Weidong Sheng , Jean-Pierre Leburton

InGaAs Quantum Dots embedded in GaAs barriers, grown in inverted tetrahedral recesses of 7 {\mu}m edge, have showed interesting characteristics in terms of uniformity and spectral narrowness of the emission. In this paper we present a study…

介观与纳米尺度物理 · 物理学 2011-04-04 L. O. Mereni , V. Dimastrodonatoa , G. Juskaa , E. Pelucchia L. O. Mereni , V. Dimastrodonatoa , G. Juskaa , E. Pelucchi

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…

介观与纳米尺度物理 · 物理学 2014-03-18 Muhammad Usman

Starting with an accurate pseudopotential description of the single-particle states, and following by configuration-interaction treatment of correlated electrons in vertically coupled, self-assembled InAs/GaAs quantum dot-molecules, we show…

材料科学 · 物理学 2009-11-11 Lixin He , Gabriel Bester , Alex Zunger

Quantum dots are small conductive regions in a semiconductor, containing a variable number of electrons (N=1 to 1000) that occupy well defined discrete quantum states. They are often referred to as artificial atoms with the unique property…

介观与纳米尺度物理 · 物理学 2007-05-23 T. H. Oosterkamp , T. Fujisawa , W. G. van der Wiel , K. Ishibashi , R. V. Hijman , S. Tarucha , L. P. Kouwenhoven

We present an optical study of closely-spaced self-assembled InAs/GaAs quantum dots. The energy spectrum and correlations between photons subsequently emitted from a single pair provide not only clear evidence of coupling between the…

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