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Related papers: Spin-polarized currents in double and triple quant…

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We demonstrate that an aperiodic array of certain quantum networks comprising magnetic and non-magnetic atoms can act as perfect spin filters for particles with arbitrary spin state. This can be achieved by introducing minimal quasi-one…

Disordered Systems and Neural Networks · Physics 2018-08-22 Amrita Mukherjee , Arunava Chakrabarti , Rudolf A. Roemer

Semiconductor point contacts can be a useful tool for producing spin-polarized currents in the presence of spin-orbit (SO) interaction. Neither magnetic fields nor magnetic materials are required. By numerical studies, we show that (i) the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mikio Eto , Tetsuya Hayashi , Yuji Kurotani

Spin-polarized transport through a double quantum dot system attached to a common superconducting lead and two ferromagnetic electrodes (fork geometry) is investigated theoretically. The key objective of the analysis is to describe the…

Mesoscale and Nanoscale Physics · Physics 2014-09-16 Piotr Trocha , Józef Barnaś

Circularly polarized optical excitation is used to demonstrate the efficient injection of spin-polarized excitons to individual self-assembled CdSe quantum dots in ZnSe barrier. The exciton spin-transfer is studied by means of…

Mesoscale and Nanoscale Physics · Physics 2014-08-14 T. Smoleński , W. Pacuski , M. Goryca , M. Nawrocki , A. Golnik , P. Kossacki

The electron-nuclei (hyperfine) interaction is central to spin qubits in solid state systems. It can be a severe decoherence source but also allows dynamic access to the nuclear spin states. We study a double quantum dot exposed to an…

Mesoscale and Nanoscale Physics · Physics 2013-06-13 Gunnar Petersen , Eric A. Hoffmann , Dieter Schuh , Werner Wegscheider , Geza Giedke , Stefan Ludwig

We theoretically study the spin-polarized transport through a single-molecule magnet, which is weakly coupled to ferromagnetic leads, by means of the rate-equation approach. We consider both the ferromagnetic and antiferromagnetic…

Mesoscale and Nanoscale Physics · Physics 2012-03-22 Haiqing Xie , Qiang Wang , Bo Chang , Hujun Jiao , J. -Q. Liang

We theoretically investigate transport signatures of quantum interference in highly symmetric double quantum dots in a parallel geometry and demonstrate that extremely weak symmetry-breaking effects can have a dramatic influence on the…

Mesoscale and Nanoscale Physics · Physics 2019-03-06 Zeng-Zhao Li , Martin Leijnse

A highly asymmetric dynamic nuclear spin pumping is observed in a single self assembled InGaAs quantum dot subject to resonant optical pumping of the neutral exciton transition leading to a large maximum polarization of 54%. This dynamic…

Mesoscale and Nanoscale Physics · Physics 2010-09-30 F. Klotz , V. Jovanov , J. Kierig , E. C. Clark , M. Bichler , G. Abstreiter , M. S. Brandt , J. J. Finley , H. Schwager , G. Giedke

We study DC charge and spin transport through a weakly coupled quantum dot, driven by a non-adiabatic periodic change of system parameters. We generalize the model of Tien and Gordon to simultaneously oscillating voltages and tunnel…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 Matthias Braun , Guido Burkard

Polynuclear magnetic molecules often present dense transmission spectra with many overlapping conduction spin channels. Single-metal complexes display a sparser density of states, which in the presence of a fixed external magnetic field…

Mesoscale and Nanoscale Physics · Physics 2017-12-19 Salvador Cardona-Serra , Alejandro Gaita-Ariño , Efrén Navarro-Moratalla , Stefano Sanvito

We calculate spin transport in two-dimensional waveguides in the presence of spatially modulated Zeeman-split energy bands. We show that in a regime where the spin evolution is predominantly adiabatic the spin backscattering rate can be…

Mesoscale and Nanoscale Physics · Physics 2012-10-16 Henri Saarikoski , Tobias Dollinger , Klaus Richter

The spin-orbit coupling influences the total spin of semiconductor quantum dots. We analyze the theoretical prediction for the combined effects of spin-orbit coupling, weak vertical magnetic fields and deformation of the dot. Our results…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Manuel Valin-Rodriguez , Antonio Puente , Llorens Serra , Enrico Lipparini

Nonequilibrium electronic transport through a quantum dot coupled to ferromagnetic leads (electrodes) is studied theoretically by the nonequilibrium Green function technique. The system is described by the Anderson model with arbitrary…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 R. Swirkowicz , M. Wilczynski , J. Barnas

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 investigate the current-voltage characteristics of a II-VI semiconductor resonant-tunneling diode coupled to a diluted magnetic semiconductor injector. As a result of an external magnetic field, a giant Zeeman splitting develops in the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. Slobodskyy , C. Gould , T. Slobodskyy , G. Schmidt , L. W. Molenkamp , D. Sanchez

Results of calculations and high source-drain transport measurements are presented which demonstrate voltage-tunable entanglement of electron pairs in lateral quantum dots. At a fixed magnetic field, the application of a judiciously-chosen…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Jordan Kyriakidis , M. Pioro-Ladriere , M. Ciorga , A. S. Sachrajda , P. Hawrylak

We propose a quantum processor based upon single-molecule magnets and spin transfer torque described by PT-symmetric quantum mechanics. In recent years PT-symmetric Hamiltonians have been used to obtain stability thresholds of various…

Mesoscale and Nanoscale Physics · Physics 2019-05-22 Aleix Bou Comas , Eugene M. Chudnovsky , Javier Tejada

By the application of an in-plane magnetic field, we demonstrate control of the fine structure polarisation splitting of the exciton emission lines in individual InAs quantum dots. The selection of quantum dots with certain barrier…

We propose schemes for generating spin currents into a semiconductor by adiabatic or non-adiabatic pumping of electrons through interacting quantum dots. The appeal of such schemes lies in the possibility to tune the pumping characteristics…

Mesoscale and Nanoscale Physics · Physics 2015-01-09 Stephan Rojek , Michele Governale , Jürgen König

We determine the spin exchange coupling J between two electrons located in two vertically tunnel-coupled quantum dots, and its variation when magnetic (B) and electric (E) fields (both in-plane and perpendicular) are applied. We predict a…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Guido Burkard , Georg Seelig , Daniel Loss
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