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We have studied the edge spin accumulation in a high mobility two-dimensional electron gas formed in a symmetric well with two subbands. This study is strongly motivated by the recent experiment of Hernandez et al. [Phys. Rev. B {\bf 88},…

Mesoscale and Nanoscale Physics · Physics 2018-09-07 Alexander Khaetskii , J. Carlos Egues

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

We propose a new mode of operation of an electron pump consisting of two weakly coupled quantum dots connected to reservoirs. An electron can be transferred within the device at zero bias voltage when it is subjected to electromagnetic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 B. L. Hazelzet , M. R. Wegewijs , T. H. Stoof , Yu. V. Nazarov

The electronic structure of strain-engineered single InGaAs/GaAs quantum dots emitting in the telecommunication O band is probed experimentally by photoluminescence excitation spectroscopy. Observed resonances can be attributed to p-shell…

A dynamical method for inelastic transport simulations in nanostructures is compared with a steady-state method based on non-equilibrium Green's functions. A simplified form of the dynamical method produces, in the steady state in the…

Mesoscale and Nanoscale Physics · Physics 2008-08-19 Eunan J. McEniry , Thomas Frederiksen , Tchavdar N. Todorov , Daniel Dundas , Andrew P. Horsfield

In this paper, we describe the growth and characterization of 530-nm-thick superlattices (100 periods) of AlxGa1-xN/AlN (x = 0, 0.1) Stranski-Krastanov quantum dots for application as the active region of electron-beam pumped ultraviolet…

Epitaxially-grown quantum well and quantum dot solar cells suffer from weak light absorption, strongly limiting their performance. Light trapping based on optical resonances is particularly relevant for such devices to increase light…

Applied Physics · Physics 2023-11-10 Maxime Giteau , Yusuke Oteki , Kento Kitahara , Naoya Miyashita , Ryo Tamaki , Yoshitaka Okada

Epitaxially-grown semiconductor quantum dots (QDs) provide an attractive platform for the development of deterministic sources of high-quality quantum states of light. Such non-classical light sources are essential for quantum information…

Mesoscale and Nanoscale Physics · Physics 2023-08-30 Lucie Leguay , Abhiroop Chellu , Joonas Hilska , Esperanza Luna , Andrei Schliwa , Mircea Guina , Teemu Hakkarainen

We adopt an atomistic pseudopotential description of the electronic structure of self-assembled, lens shaped InAs quantum dots within the ``linear combination of bulk bands'' method. We present a detailed comparison with experiment,…

Materials Science · Physics 2009-10-31 A. J. Williamson , L. W. Wang , Alex Zunger

We studied a vertical ``quantum dot molecule'', where one of the dots is occupied with electrons and the other with holes. We find that different phases occur in the ground state, depending on the carrier density and the interdot distance.…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 K. Karkkainen , M. Koskinen , M. Manninen , S. M. Reimann

Quantum parametric amplifiers typically generate by operating in proximity to a point of dynamical instability. We consider an alternate general strategy where quantum-limited, large-gain amplification is achieved without any proximity to a…

Quantum Physics · Physics 2025-03-06 A. Metelmann , O. Lanes , T-Z. Chien , A. McDonald , I. Tsiamis , M. Hatridge , A. A. Clerk

Scattering of carriers between spatially separated zero dimensional states has been observed in a system of self-assembled In_{0.55}Al_{0.45}As quantum dots. We believe the interdot tunneling is mediated by localized states below the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 H. D. Robinson , B. B. Goldberg , J. L. Merz

We show that quantum dots and quantum wires are formed underneath metal electrodes deposited on a planar semiconductor heterostructure containing a quantum well. The confinement is due to the self-focusing mechanism of an electron wave…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 S. Bednarek , B. Szafran , R. Dudek , K. Lis

We report the observation of fractional quantum Hall (FQH) effects in a two-dimensional electron gas (2DEG) confined to an InAs/AlGaSb quantum well, using a dual-gated Hall-bar device allowing for the independent control of the vertical…

Mesoscale and Nanoscale Physics · Physics 2022-02-17 S. Komatsu , H. Irie , T. Akiho , T. Nojima , T. Akazaki , K. Muraki

We have investigated the band-gap pressure coefficients of self-assembled InAs/GaAs quantum dots by calculating 17 systems with different quantum dot shape, size, and alloying profile using atomistic empirical pseudopotential method within…

Materials Science · Physics 2009-11-10 Jun-Wei Luo , Shu-Shen Li , Jian-Bai Xia , Lin-Wang Wang

We investigate non-linear magneto-transport in a Hall bar device made from a strained InGaAs/InP quantum well: a material system with attractive spintronic properties. From extensive maps of the longitudinal differential resistance (r_xx)…

Disordered Systems and Neural Networks · Physics 2018-10-31 V. Yu , M. Hilke , P. J. Poole , S. Studenikin , D. G. Austing

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…

Mesoscale and Nanoscale Physics · Physics 2011-04-04 L. O. Mereni , V. Dimastrodonatoa , G. Juskaa , E. Pelucchia L. O. Mereni , V. Dimastrodonatoa , G. Juskaa , E. Pelucchi

In traditional approaches of obtaining quantized acoustoelectric current, a narrow channel is fabricated to form quantum dots, which hold a fixed number of electrons at a certain depth. We propose a natural way of forming quantum dots…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Xiang-Song Chen

We study theoretically phonon-assisted relaxation and tunnelling in a system composed of a quantum dot which is coupled to a quantum well. Within the kp method combined with the L\"owdin elimination, we calculate the electron states. We…

Mesoscale and Nanoscale Physics · Physics 2017-12-11 Adam Mielnik-Pyszczorski , Krzysztof Gawarecki , Paweł Machnikowski

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