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Magnetically doped semiconductors are well known for their giant Zeeman splittings which can reach several meV even in relatively small external magnetic fields. After preparing a nonequilibrium exciton distribution via optical excitation,…

Mesoscale and Nanoscale Physics · Physics 2019-02-06 Florian Ungar , Moritz Cygorek , Vollrath Martin Axt

We propose an ac current source that can be tuned from a pure charge to a pure spin current source. The device consists of two mesoscopic capacitors attached to a two-dimensional strip of a topological insulator. The change from charge to…

Mesoscale and Nanoscale Physics · Physics 2014-07-14 Patrick P. Hofer , Hugo Aramberri , Christoph Schenke , Pierre A. L. Delplace

We analyze cotunneling transport through two quantum dots in series weakly coupled to external ferromagnetic leads. In the Coulomb blockade regime the electric current flows due to third-order tunneling, while the second-order…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 I. Weymann

We investigate the spin-resolved electron dynamics in a double quantum dot driven by ultrafast asymmetric electromagnetic pulses. Using a analytical model we show that applying an appropriate pulse sequence allows to control coherently the…

Mesoscale and Nanoscale Physics · Physics 2017-02-15 J. Waetzel , A. S. Moskalenko , J. Berakdar

We present a simple device made of two small capacitively coupled quantum dots in parallel. This set-up can be used as an efficient "Stern-Gerlach" spin filter, able to simultaneously produce, from a normal metallic lead, two oppositely…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Denis Feinberg , Pascal Simon

We consider the hyperfine-mediated transition rate between Zeeman split spin states of the lowest orbital level in a GaAs quantum dot. We separate the hyperfine Hamiltonian into a part which is diagonal in the orbital states and another one…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Sigurdur I. Erlingsson , Yuli V. Nazarov

We study a double quantum dot each dot of which is tunnel-coupled to superconducting leads. In the Coulomb blockade regime, a spin-dependent Josephson coupling between two superconductors is induced, as well as an antiferromagnetic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Mahn-Soo Choi , C. Bruder , Daniel Loss

We have investigated the transport characteristics of an electron pump consisting of an asymmetric double quantum dot at zero bias voltage which is subject to electromagnetic radiation. Depending on the energies of the intermediate states…

Mesoscale and Nanoscale Physics · Physics 2008-02-03 T. H. Stoof , Yu. V. Nazarov

We have fabricated all II-VI semiconductor resonant tunneling diodes based on the (Zn,Mn,Be)Se material system, containing dilute magnetic material in the quantum well, and studied their current-voltage characteristics. When subjected to an…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 A. Slobodskyy , C. Gould , T. Slobodskyy , C. R. Becker , G. Schmidt , L. W. Molenkamp

Non-equilibrium spin transport through an interacting quantum dot is analyzed. The coherent spin oscillations in the dot provide a generating source for spin current. In the interacting regime, the Kondo effect is influenced in a…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Ping Zhang , Qi-Kun Xue , X. C. Xie

We report a study of spin dependent transport in a system composed of a quantum dot coupled to a normal metal lead and a ferromagnetic lead (NM-QD-FM). We use the master equation approach to calculate the spin-resolved currents in the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 F. M. Souza , J. C. Egues , A. P. Jauho

Motivated by the experimental evidence of the Nagaoka ferromagnetism in quantum dot systems by Dehollain et al [1], we search for possible confirmation of such kind of ferromagnetism by analyzing the spin-resolved transport properties of a…

Mesoscale and Nanoscale Physics · Physics 2024-10-04 Piotr Trocha , Emil Siuda , Ireneusz Weymann

We study a double quantum dot system with two interacting electrons in the presence of a time-dependent periodic (AC) electric field and spin-orbit interaction. We focus on the phenomenon of Coherent Destruction of Tunneling (CDT) for an…

Mesoscale and Nanoscale Physics · Physics 2014-07-17 K. Rahim , U. Hasan , K. Sabeeh

In this paper we show that it is possible to switch the spin polarization of the photocurrent signal obtained from a single self-assembled quantum dot photodiode under the effect of elliptically polarized light by just increasing the light…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 J. M. Villas-Boas , Sergio E. Ulloa , A. O. Govorov

We present an approach for entangling electron spin qubits localized on spatially separated impurity atoms or quantum dots via a multi-electron, two-level quantum dot. The effective exchange interaction mediated by the dot can be understood…

Mesoscale and Nanoscale Physics · Physics 2015-06-10 V. Srinivasa , H. Xu , J. M. Taylor

Rapid coherent control of electron spin states is required for implementation of a spin-based quantum processor. We demonstrate coherent control of electronic spin states in a double quantum dot by sweeping an initially prepared spin…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 J. R. Petta , H. Lu , A. C. Gossard

We propose a new device to create a tunable all-electric spin polarizer: a quantum point contact (QPC) with four gates -- two in-plane side gates in series. The first pair of gates, near the source, is asymmetrically biased to create spin…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 J. Charles , N. Bhandari , J. Wan , M. Cahay , R. S. Newrock

Despite its potential for device application, the non-magnetic Zeeman effect has only been predicted and observed in two-dimensional compounds. We demonstrate that non-centrosymmetric three-dimensional compounds can also exhibit a…

Materials Science · Physics 2022-02-11 Carlos Mera Acosta , Adalberto Fazzio , Gustavo M. Dalpian

Altermagnets exhibit momentum-dependent spin splitting despite having zero net magnetization. This enables a spin-splitter effect in which an external electric field generates transverse spin currents by separating oppositely polarized…

Mesoscale and Nanoscale Physics · Physics 2026-02-27 Sanjay Sarkar , Sayan Sarkar , Amit Agarwal

For a double quantum dot system in a parallel geometry, we demonstrate that by combining the effects of a flux and driving an electrical current through the structure, the spin correlations between electrons localized in the dots can be…

Strongly Correlated Electrons · Physics 2015-06-15 C. A. Büsser , F. Heidrich-Meisner