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The electron and hole states in a CdTe quantum dot containing a single magnetic impurity in an external magnetic field are investigated, using the multiband approximation which includes the heavy hole-light hole coupling effects. The…

Mesoscale and Nanoscale Physics · Physics 2010-08-10 Aram Manaselyan , Tapash Chakraborty

We briefly review the physics of gate operations between quantum dot spin-qubits and analyze the dynamics of quantum entanglement in such processes. The indistinguishable character of the electrons whose spins realize the qubits gives rise…

Condensed Matter · Physics 2007-05-23 John Schliemann , Daniel Loss

The emission of circularly polarized light from a single quantum dot relies on the injection of carriers with well-defined spin polarization. Here we demonstrate single dot electroluminescence (EL) with a circular polarization degree up to…

Irradiating a semiconductor with circularly polarized light creates spin-polarized charge carriers. If the material contains atoms with non-zero nuclear spin, they interact with the electron spins via the hyperfine coupling. Here, we…

Mesoscale and Nanoscale Physics · Physics 2016-09-09 Raphael W. Mocek , Danil O. Tolmachev , Giovanni Cascio , Dieter Suter

We present a theoretical analysis of dynamic spin injection due to spin-dependent tunneling between a quantum well (QW) and a bound state split in spin projection due to an exchange interaction or external magnetic field. We focus on the…

Mesoscale and Nanoscale Physics · Physics 2018-06-06 N. S. Maslova , I. V. Rozhansky , V. N. Mantsevich , P. I. Arseyev , N. S. Averkiev , E. Lahderanta

We study the spin and charge dynamics of electrons in n-doped II--VI semiconductor multiple quantum wells when one or more quantum wells are doped with Mn. The interplay between strongly nonlinear inter-well charge transport and the large…

Condensed Matter · Physics 2009-11-07 Manuel Bejar , David Sanchez , Gloria Platero , A. H. MacDonald

We use quantum optimal control theory algorithms to design external electric fields that drive the coupled spin and orbital dynamics of an electron in a double quantum dot, subject to the spin-orbit interaction and Zeeman magnetic fields.…

Mesoscale and Nanoscale Physics · Physics 2016-02-17 J. A. Budagosky , D. V. Khomitsky , E. Ya. Sherman , Alberto Castro

The spin dynamics of positively (X$^{+}$) and negatively (X$^{-}$) charged excitons in InP/In$_{0.48}$Ga$_{0.52}$P quantum dots subject to a magnetic field is studied. We find that a characteristic feature of the system under study is the…

Mesoscale and Nanoscale Physics · Physics 2019-12-18 S. V. Nekrasov , I. A. Akimov , Yu. G. Kusrayev , D. R. Yakovlev , M. Bayer

The dominant source of decoherence for an electron spin in a quantum dot is the hyperfine interaction with the surrounding bath of nuclear spins. The decoherence process may be slowed down by subjecting the electron spin to suitable…

Mesoscale and Nanoscale Physics · Physics 2017-08-23 Wenxian Zhang , V. V. Dobrovitski , Lea F. Santos , Lorenza Viola , B. N. Harmon

We report circular-to-linear and linear-to-circular conversion of optical polarization by semiconductor quantum dots. The polarization conversion occurs under continuous wave excitation in absence of any magnetic field. The effect…

We propose a new method for dynamic nuclear polarisation in a quasi one-dimensional quantum wire utilising the spin-orbit interaction, the hyperfine interaction, and a finite source-drain potential difference. In contrast with current…

Mesoscale and Nanoscale Physics · Physics 2008-03-05 V. Tripathi , A. C. H. Cheung , N. R. Cooper

We report on both experimental and theoretical study of conduction-electron spin polarization dynamics achieved by pulsed optical pumping at room temperature in GaAs(1-x)N(x) alloys with a small nitrogen content (x = 2.1, 2.7, 3.4%). It is…

Materials Science · Physics 2015-06-25 V. K. Kalevich , A. Yu. Shiryaev , E. L. Ivchenko , A. Yu. Egorov , L. Lombez , D. Lagarde , X. Marie , T. Amand

We report electronic control and measurement of an imbalance between spin-up and spin-down electrons in micron-scale open quantum dots. Spin injection and detection was achieved with quantum point contacts tuned to have spin-selective…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 E. J. Koop , B. J. van Wees , D. Reuter , A. D. Wieck , C. H. van der Wal

Dynamics is studied of an electron in a quasi-one-dimensional ballistic ring under circularly polarized electromagnetic field propagating along the normal to the ring plane. The average emission intensity from the ring is calculated. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 E. M. Epshtein , E. G. Fedorov , G. M. Shmelev

We show how a spin interaction between electrons localized in neighboring quantum dots can be induced and controlled optically. The coupling is generated via virtual excitation of delocalized excitons and provides an efficient coherent…

Condensed Matter · Physics 2009-11-07 C. Piermarocchi , Pochung Chen , L. J. Sham , D. G. Steel

We show that when an electron or photon propagates in a cylindrically symmetric waveguide, its spin angular momentum (SAM) and its orbital angular momentum (OAM) interact. Remarkably, we find that the dynamics resulting from this spin-orbit…

Quantum Physics · Physics 2009-12-09 C. C. Leary , M. G. Raymer , S. J. van Enk

We study the shot noise (nonequilibrium current fluctuation) associated with dynamic nuclear polarization in a nonequilibrium quantum wire (QW) fabricated in a two-dimensional electron gas. We observe that the spin-polarized conductance…

We study the spin-spin coupling between two single-electron quantum dots due to the Coulomb and spin-orbit interactions, in the absence of tunneling between the dots. We find an anisotropic XY spin-spin interaction that is proportional to…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mircea Trif , Vitaly N. Golovach , Daniel Loss

Spin-polarization effects of an ultrarelativistic electron beam head-on colliding with an ultraintense two-color laser pulse are investigated comprehensively in the quantum radiation-dominated regime. We employ a Monte Carlo method, derived…

Plasma Physics · Physics 2019-09-18 Huai-Hang Song , Wei-Min Wang , Jian-Xing Li , Yan-Fei Li , Yu-Tong Li

We present an investigation of the electron spin dynamics in an ensemble of singly-charged quantum dots subject to an external magnetic field and laser pumping with circularly polarized light. The spectral laser width is tailored such that…

Mesoscale and Nanoscale Physics · Physics 2018-12-05 Andreas Fischer , Eiko Evers , Steffen Varwig , Alex Greilich , Manfred Bayer , Frithjof B. Anders