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We introduce a method for solving the problem of an externally controlled electron spin in a quantum dot interacting with host nuclei via the hyperfine interaction. Our method accounts for generalized (non-unitary) evolution effected by…

Mesoscale and Nanoscale Physics · Physics 2011-07-21 Edwin Barnes , Sophia E. Economou

Properties of the "electron gas" - in which conduction electrons interact by means of Coulomb forces but ionic potentials are neglected - change dramatically depending on the balance between kinetic energy and Coulomb repulsion. The limits…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Amit Ghosal , A. D. Guclu , C. J. Umrigar , Denis Ullmo , Harold U. Baranger

The spectral properties of up to four interacting electrons confined within a quasi one--dimensional system of finite length are determined by numerical diagonalization including the spin degree of freedom. The ground state energy is…

Condensed Matter · Physics 2009-10-22 Wolfgang Haeusler , Bernhard Kramer , PTB Braunschweig

The mesoscopic spin system formed by the 10E4-10E6 nuclear spins in a semiconductor quantum dot offers a unique setting for the study of many-body spin physics in the condensed matter. The dynamics of this system and its coupling to…

Mesoscale and Nanoscale Physics · Physics 2013-01-11 Bernhard Urbaszek , Xavier Marie , Thierry Amand , Olivier Krebs , Paul Voisin , Patrick Maletinsky , Alexander Hogele , Atac Imamoglu

A linearly coupled chain of spin-polarized quantum dots is investigated under the condition that the number of electrons is equal to or less than the number of the dots. The chemical potential of the system, $\mu_{N}=E(N)-E(N-1)$,…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Kicheon Kang , Min-Chul Cha , S. -R. Eric Yang

We investigated the time dependence of two-electron spin states in a double quantum dot fabricated in an InAs nanowire. In this system, spin-orbit interaction has substantial influence on the spin states of confined electrons. Pumping…

Mesoscale and Nanoscale Physics · Physics 2009-04-30 A. Pfund , I. Shorubalko , K. Ensslin , R. Leturcq

Enhancement of the electron spin polarization in a correlated two-layer two-dimensional electron system at a total Landau level filling factor of one is reported. Using resistively detected nuclear magnetic resonance, we demonstrate that…

Strongly Correlated Electrons · Physics 2015-04-30 L. Tiemann , W. Wegscheider , M. Hauser

The control of nuclear spins in quantum dots is essential to explore their many-body dynamics and exploit their prospects for quantum information processing. We present a unique combination of dynamic nuclear spin polarization and…

Mesoscale and Nanoscale Physics · Physics 2015-12-16 Florian Forster , Max Mühlbacher , Dieter Schuh , Werner Wegscheider , Geza Giedke , Stefan Ludwig

The dynamics of the coupled electron-nuclear spin system is studied in an ensemble of singly-charged (In,Ga)As/GaAs quantum dots (QDs) using periodic optical excitation at 1 GHz repetition rate. In combination with the electron-nuclei…

Mesoscale and Nanoscale Physics · Physics 2021-08-11 E. Evers , N. E. Kopteva , I. A. Yugova , D. R. Yakovlev , M. Bayer , A. Greilich

Few-electron systems confined in a quantum dot laterally coupled to a surrounding quantum ring in the presence of an external magnetic field are studied by exact diagonalization. The distribution of electrons between the dot and the ring is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 B. Szafran , F. M. Peeters , S. Bednarek

We study theoretically the electron spin noise in quantum dots under non-equilibrium conditions caused by the pumping by a train of circularly polarized optical pulses. In such a situation, the nuclear spins are known to adjust in such a…

Mesoscale and Nanoscale Physics · Physics 2018-08-01 Natalie Jäschke , Frithjof B. Anders , Mikhail M. Glazov

Controlling electron spins strongly coupled to magnetic and nuclear spins in solid state systems is an important challenege in the field of spintronics and quantum computation. We show here that electron droplets with no net spin in…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 Ramin M. Abolfath , Marek Korkusinski , Thomas Brabec , Pawel Hawrylak

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…

Electron transport in a new low-dimensional structure - the nuclear spin polarization induced quantum wire (NSPI QW) is theoretically studied. In the proposed system the local nuclear spin polarization creates the effective hyperfine field…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Yu. V. Pershin , S. N. Shevchenko , I. D. Vagner , P. Wyder

Hyperfine coupling of electron spins to nuclear spins is studied for a GaAs-based double quantum dot in the spin blockade regime where the electron conduction is mostly blocked by Pauli effect unless the electron spin state in the double…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Keiji Ono , Seigo Tarucha

We study the formation and characteristics of "spin droplets",i.e., compact spin-polarized configurations in the highest occupied Landau level, in an etched quantum Hall device at filling factors $2\leq\nu\leq3$. The confining potential for…

Mesoscale and Nanoscale Physics · Physics 2015-06-12 H. Atci , U. Erkarslan , A. Siddiki , E. Rasanen

We review recent studies on spin decoherence of electrons and holes in quasi-two-dimensional quantum dots, as well as electron-spin relaxation in nanowire quantum dots. The spins of confined electrons and holes are considered major…

Mesoscale and Nanoscale Physics · Physics 2009-07-28 Jan Fischer , Mircea Trif , W. A. Coish , Daniel Loss

We study quantum states of electrons in magnetically doped quantum dots as a function of exchange coupling between electron and impurity spins, the strength of Coulomb interaction, confining potential, and the number of electrons. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Ramin M. Abolfath , Pawel Hawrylak , Igor Zutic

We present a numerical study of spin relaxation in a semiclassical electron ensemble in a large ballistic quantum dot. The dot is defined in a GaAs/AlGaAs heterojunction system with a two-dimensional electron gas, and relaxation occurs due…

Mesoscale and Nanoscale Physics · Physics 2008-04-21 E. J. Koop , B. J. van Wees , C. H. van der Wal

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