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Related papers: Spin filtering through excited states in double qu…

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We study the spin-dependent transport properties of a spin valve based on a double quantum dot. Each quantum dot is assumed to be strongly coupled to its own ferromagnetic lead, while the coupling between the dots is relatively weak. The…

Mesoscale and Nanoscale Physics · Physics 2021-07-21 Patrycja Tulewicz , Kacper Wrzesniewski , Szabolcs Csonka , Ireneusz Weymann

We simulate the control of the spin states in a two-electron double quantum dot when an external detuning potential is used for passing the system through an anticrossing. The hyperfine coupling of the electron spins with the surrounding…

Mesoscale and Nanoscale Physics · Physics 2011-04-12 Jani Särkkä , Ari Harju

A quantum dot with spin-orbit interaction can work as an efficient spin filter if it is connected to N (> 2) external leads via tunnel barriers. When an unpolarized current is injected to a quantum dot from a lead, polarized currents are…

Mesoscale and Nanoscale Physics · Physics 2010-12-30 Mikio Eto , Tomohiro Yokoyama

The influence of external magnetic field switching $"$on$"$ and $"$off$"$ on the non-stationary spin-polarized currents in the system of correlated single-level quantum dot coupled to non-magnetic electronic reservoirs has been analyzed. It…

Mesoscale and Nanoscale Physics · Physics 2017-06-29 V. N. Mantsevich , N. S. Maslova , P. I. Arseyev

We analyze spin-dependent transport through a spin-diode in the presence of spin-flip and under influence of temperature bias. The current polarization and the spin accumulation are investigated in detail by means of reduced density matrix.…

Mesoscale and Nanoscale Physics · Physics 2012-04-10 M. Bagheri Tagani , H. Rahimpour Soleimani

In terms of the exact quantum master equation solution for open electronic systems, the coherent dynamics of two charge states described by two parallel quantum dots with one fully polarized electron on either dot is investigated in the…

Mesoscale and Nanoscale Physics · Physics 2013-08-20 Jinshuang Jin , Wei-Min Zhang , Matisse Wei-Yuan Tu , Nien-En Wang

A double-quantum-dot coupled to electrodes with spin-dependent splitting of chemical potentials (spin bias) is investigated theoretically by means of the Green's functions formalism. By applying a large spin bias, the quantum spin in a…

Mesoscale and Nanoscale Physics · Physics 2008-06-16 Hai-Zhou Lu , Shun-Qing Shen

Nuclear spin polarization can be pumped into spin-blocked quantum dots by multiple Landau- Zener passages through singlet-triplet anticrossings. By numerical simulations of realistic systems including approximately $10^7$ nuclear spins…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Arne Brataas , Emmanuel I. Rashba

We review progress on the spintronics proposal for quantum computing where the quantum bits (qubits) are implemented with electron spins. We calculate the exchange interaction of coupled quantum dots and present experiments, where the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hans-Andreas Engel , L. P. Kouwenhoven , Daniel Loss , C. M. Marcus

We propose a scheme to manipulate the spin coherence in vertically coupled GaAs double quantum dots. Up to {\em ten} orders of magnitude variation of the spin relaxation and {\em two} orders of magnitude variation of the spin dephasing can…

Materials Science · Physics 2008-03-19 Y. Y. Wang , M. W. Wu

The paper proposes the method to analyze the internal dynamics of nanoscopic systems by periodic modulation of the electrochemical potentials of the attached leads and measuring the time-averaged current. The idea is presented using the…

Mesoscale and Nanoscale Physics · Physics 2017-11-15 Krzysztof Ptaszynski

In many electron spin qubit systems coherent control is impaired by the fluctuating nuclear spin bath of the host material. Previous experiments have shown dynamic nuclear polarization with feedback to significantly prolong the…

Mesoscale and Nanoscale Physics · Physics 2015-12-02 Stefanie Tenberg , Robert P. G. McNeil , Sebastian Rubbert , Hendrik Bluhm

Numerical calculations indicate that by suitably controlling the individual gate voltages of a capacitively coupled parallel double quantum dot, with each quantum dot coupled to one of two independent non-magnetic channels, this system can…

Mesoscale and Nanoscale Physics · Physics 2013-03-05 Carlos A. Busser , Adrian E. Feiguin , George B. Martins

The impact of control sequences on the environmental coupling of a quantum system can be described in terms of a filter. Here we analyze how the coherent evolution of two interacting spins subject to periodic control pulses, at the example…

Quantum Physics · Physics 2015-08-20 Andreas Albrecht , Martin B. Plenio

We propose three different mechanisms for pumping spin-polarized currents in a ballistic circuit using a time-dependent magnetic field acting on an asymmetrically connected quantum ring at half filling. The first mechanism works thanks to a…

Mesoscale and Nanoscale Physics · Physics 2014-02-26 Michele Cini , Stefano Bellucci

We show that the tunable hybridization between two lateral quantum dots connected to non-magnetic current leads in a `hanging-dot' configuration that can be used to implement a bipolar spin filter. The competition between Zeeman, exchange…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 F. Mireles , E. Cota , F. Rojas , S. E. Ulloa

All-electric devices for the generation and filtering of spin currents are of crucial importance for spintronics experiments and applications. Here we consider a quantum dot between two metallic leads in the presence of spin-orbit coupling,…

Mesoscale and Nanoscale Physics · Physics 2011-06-08 Valentina Brosco , Markus Jerger , Pablo San-Jose , Gergely Zarand , Alexander Shnirman , Gerd Schön

A new way of getting controlled spin dependent transport through a two-terminal bridge setup is explored. The system comprises a magnetic quantum ring which is directly coupled to a magnetic quantum wire and subjected to an in-plane…

Mesoscale and Nanoscale Physics · Physics 2015-07-09 Santanu K. Maiti

A new generalised group-theoretical approach, based on master Maxwell-pseudospin equations, is proposed to explain recently observed enhanced circular dichroism in the excited state emission from p-doped quantum dot ensembles under resonant…

Mesoscale and Nanoscale Physics · Physics 2013-01-30 G. Slavcheva

It was proposed that a double quantum dot can be used to be a detector of spin bias. Electron transport through a double quantum dot is investigated theoretically when a pure spin bias is applied on two conducting leads contacted to the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Qing-feng Sun , Yanxia Xing , Shun-Qing Shen