English
Related papers

Related papers: Carrier Dynamics in Submonolayer InGaAs/GaAs Quant…

200 papers

We present a microscopic theory of transport through quantum dot set-ups coupled to superconducting leads. We derive a master equation for the reduced density matrix to lowest order in the tunneling Hamiltonian and focus on quasiparticle…

Mesoscale and Nanoscale Physics · Physics 2013-06-24 Sebastian Pfaller , Andrea Donarini , Milena Grifoni

We report quantum dots fabricated on very shallow 2-dimensional electron gases, only 30 nm below the surface, in undoped GaAs/AlGaAs heterostructures grown by molecular beam epitaxy. Due to the absence of dopants, an improvement of more…

Mesoscale and Nanoscale Physics · Physics 2015-03-19 W. Y. Mak , F. Sfigakis , K. Das Gupta , O. Klochan , H. E. Beere , I. Farrer , J. P. Griffiths , G. A. C. Jones , A. R. Hamilton , D. A. Ritchie

We describe the optical emission and the carrier dynamics of an ensemble of self-assembled GaAs quantum dots embedded in GaP(001). The QD formation is driven by the 3.6 % lattice mismatch between GaAs and GaP in Stranski-Krastanow mode…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 S. Dadgostar , J. Schmidtbauer , T. Boeck , A. Torres , O. Martínez , J. Jiménez , J. W. Tomm , A. Mogilatenko , W. T. Masselink , F. Hatami

Shallow GaAs/InGaAs/GaAs quantum well structures with and without a three monolayer thick AlAs central barrier have been investigated for different well widths and Si doping levels. The transport parameters are determined by resistivity…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 V. A. Kulbachinskii , I. S. Vasil'evskii , R. A. Lunin , G. Galistu , A. de Visser , G. B. Galiev , S. S. Shirokov , V. G. Mokerov

Spatially indirect Type-II band alignment in magnetically-doped quantum dot (QD) structures provides unexplored opportunities to control the magnetic interaction between carrier wavefunction in the QD and magnetic impurities. Unlike the…

Mesoscale and Nanoscale Physics · Physics 2018-01-17 P. Zhang , T. Norden , J. M. Pientka , R. Oszwałdowski , A. Najafi , B. Barman , Y. Tsai , W-C. Fan , W-C. Chou , J. E. Han , I. Žutić , B. D. McCombe , A. Petrou

We report on the observation of photoluminescence from positive, neutral and negative charge states of single semiconductor quantum dots. For this purpose we designed a structure enabling optical injection of a controlled unequal number of…

We demonstrate charge tuning in strain free GaAs/AlGaAs quantum dots (QDs) grown by droplet epitaxy on a GaAs(111)A substrate. Application of a bias voltage allows the controlled charging of the QDs from $-3|e|$ to $+2|e|$. The resulting…

Mesoscale and Nanoscale Physics · Physics 2014-08-29 L. Bouet , M. Vidal , T. Mano , N. Ha , T. Kuroda , M. V. Durnev , M. M. Glazov , E. L. Ivchenko , X. Marie , T. Amand , K. Sakoda , G. Wang , B. Urbaszek

Solvothermal synthesis of MoS2 based quantum dots (QDs) and the performance evaluation of bare QDs for the detection of aqueous As (III) oxidative state at room temperature and neutral pH over an extremely wide range (0.1 ppb to 1000 ppb)…

Applied Physics · Physics 2021-07-14 Jamilur R. Ansari , Md. Farhan Naseh , Neelam Singh , Tapan Sarkar , Anindya Datta

This study systematically investigates the photoconductive properties of low-temperature-grown Beryllium (Be)-doped InGaAs/InAlAs strain-balanced superlattices (SLs) grown by molecular beam epitaxy under stationary growth conditions on…

A semiconductor quantum dot (QD) can generate highly indistinguishable single-photons at a high rate. For application in quantum communication and integration in hybrid systems, control of the QD optical properties is essential.…

The influence of indium percentage on dynamical characteristics of InxGa1-xAs/GaAs(001) quantum dot lasers (QDLs) is investigated. Energy levels of self-organized truncated-cone-shape QDs are calculated by means of the eight-band k.p model,…

Computational Physics · Physics 2015-11-04 Mahdi Ahmadi Borji , Esfandiar Rajaei

The optical and electronic properties of 2D semiconductors are intrinsically linked via the strong interactions between optically excited bound species and free carriers. Here we use near-field scanning microwave microscopy (SMM) to image…

The use of low-dimensional structures such as quantum wells, wires or dots in the absorbing regions of solar cells strongly affects the spectral response of the latter, the spectral properties being drastically modified by quantum…

Mesoscale and Nanoscale Physics · Physics 2012-06-14 U. Aeberhard

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

Self-assembled InAs quantum dots (QDs) grown on GaAs(001) surface by molecular beam epitaxy under continuous and growth-interruption modes exhibit two families of QDs, quasi-3D (Q3D) and 3D QDs, whose volume density evolution is…

Materials Science · Physics 2009-11-13 A. Balzarotti

In this paper we report on a comparative study of the low temperature emission and polarisation properties of InGaN/GaN quantum wells (QWs) grown on nonpolar a-plane and m-plane free-standing bulk GaN substrates where the In content varied…

Mesoscale and Nanoscale Physics · Physics 2016-12-20 D. Kundys , D. Sutherland , M. Davies , F. Oehler , J. Griffiths , P. Dawson , M. J. Kappers , C. J. Humphreys , S. Schulz , F. Tang , R. A. Oliver

Magnetotransport properties of a pseudomorphic GaAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure are investigated in pulsed magnetic fields up to 50 T and at temperatures of T=1.4 K and 4.2 K. The structure studied consists of a Si…

Herein, $\mathrm{MoS_{2}}$ quantum dot (QDs) with controlled optical, structural, and electronic properties are synthesized using the femtosecond pulsed laser ablation in liquid (fs-PLAL) technique by varying pulse-width, ablation power,…

We present a theoretical analysis of intraband optical transitions from the intermediate pseudo-band of confined states to the conduction band in a finite, inhomogeneous stack of self-assembled semiconductor quantum dots. The chain is…

Mesoscale and Nanoscale Physics · Physics 2015-03-20 Igor Bragar , Paweł Machnikowski

The electronic continuum states of InAs/GaAs semiconductor quantum dots embedded in a GaAs/AlAs superlattice are theoretically investigated and the far infrared absorption spectra are calculated for a variety of structures and…

Other Condensed Matter · Physics 2009-11-11 Duc Phuong Nguyen , Nicolas Regnault , Robson Ferreira , Gerald Bastard