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Related papers: Spin filters with Fano dots

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We study the nonequilibrium spin transport through a quantum dot containing two spin levels coupled to the magnetic electrodes. A formula for the spin-dependent current is obtained and is applied to discuss the linear conductance and…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Ping Zhang , Qi-Kun Xue , Yu-Peng Wang , X. C. Xie

The effect of magnetic impurities on the ballistic conductance of nanocontacts is, as suggested in recent work, amenable to ab initio study \cite{naturemat}. Our method proceeds via a conventional density functional calculation of spin and…

Strongly Correlated Electrons · Physics 2012-01-17 P. P. Baruselli , A. Smogunov , M. Fabrizio , E. Tosatti

We predict a new zero-bias anomaly in the differential conductance through a quantum dot coupled to two ferromagnetic leads with antiparallel magnetization. The anomaly differs in origin and properties from other anomalies in transport…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Ireneusz Weymann , Józef Barnaś , Jürgen König , Jan Martinek , Gerd Schön

We present measurements on the Kondo-effect in a small quantum dot connected strongly to one lead and weakly to the other. The conductance of the dot reveals an offset of the Kondo resonance at zero magnetic field. While the resonance…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 F. Simmel , R. H. Blick , J. P. Kotthaus , W. Wegscheider , M. Bichler

We investigate the linear and nonlinear transport through a single level quantum dot connected to two ferromagnetic leads in Kondo regime, using the slave-boson mean field approach for finite on-site Coulomb repulsion. We find that for…

Condensed Matter · Physics 2007-05-23 Jing Ma , Bing Dong , X. L. Lei

Transport measurements are presented on a quantum ring that is tunnel-coupled to a quantum dot. When the dot is in the Coulomb blockade regime, but strongly coupled to the open ring, Fano line shapes are observed in the current through the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. Fuhrer , P. Brusheim , T. Ihn , M. Sigrist , K. Ensslin , W. Wegscheider , M. Bichler

We review the mechanisms of low-temperature electron transport across a quantum dot weakly coupled to two conducting leads. Conduction in this case is controlled by the interaction between electrons. At temperatures moderately lower than…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 L. I. Glazman , M. Pustilnik

We show that a strongly correlated quantum dot embedded in an Aharonov-Bohm interferometer can be used to filter both charge and spin at zero voltage bias. The magnitude with which the Aharonov-Bohm arm is coupled to the system controls the…

Strongly Correlated Electrons · Physics 2009-11-13 R. J. Heary , J. E. Han , Lingyin Zhu

Spin-polarized transport through a quantum dot side attached to a topological superconductor and coupled to a pair of normal leads is discussed in Coulomb and Kondo regimes. For discussion of Coulomb range equation of motion method with…

Mesoscale and Nanoscale Physics · Physics 2023-07-19 D. Krychowski , S. Lipiński , G. Cuniberti

We propose a nanoscale device consisting of a double quantum dot with a full exchange and pair hopping interaction. In this design, the current can only flow through the upper dot, but is sensitive to the spin state of the lower dot. The…

Mesoscale and Nanoscale Physics · Physics 2025-02-25 Pierre Lombardo , Imam Makhfudz , Steffen Schäfer , Roland Hayn

Noise measurements provide a valuable tool for revealing spin polarization effects in the electronic transport through quantum coherent conductors. We present an extension of the Landauer description of shot noise to include…

Mesoscale and Nanoscale Physics · Physics 2026-05-07 Marcel Strohmeier , Samanwita Biswas , Wolfgang Belzig , Regina Hoffmann-Vogel , Elke Scheer

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 demonstrate theoretically how the Kondo effect may be observed in the transport of spinless electrons through a quantum dot. The role of conduction electron spin is played by a lead index. The Kondo effect takes place if there are two…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. G. Silvestrov , Y. Imry

We observe a strong Kondo effect in a semiconductor quantum dot when a small magnetic field is applied. The Coulomb blockade for electron tunneling is overcome completely by the Kondo effect and the conductance reaches the unitary-limit…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 W. G. van der Wiel , S. De Franceschi , T. Fujisawa , J. M. Elzerman , S. Tarucha , L. P. Kouwenhoven

We investigate the influence of spin-orbit coupling on the Kondo effects in carbon nanotube quantum dots, using the numerical renormalization group technique. A sufficiently large spin-orbit coupling is shown to destroy the SU(4) Kondo…

Strongly Correlated Electrons · Physics 2010-03-11 Martin R. Galpin , Frederic W. Jayatilaka , David E. Logan , Frithjof B. Anders

Motivated by recent experiments, in which the Kondo effect has been observed for the first time in a double quantum-dot structure, we study electron transport through a system consisting of two ultrasmall, capacitively-coupled dots with…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Teemu Pohjola , Herbert Schoeller , Gerd Schön

The zero bias conductance of quantum dots coupled to ferromagnetic leads is investigated. In the strong coupling regime, it is found that the conductance is a non-monotonic function of the angle between the magnetisation directions in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 J. Fransson

A numerically exact calculation of the T=0 transport properties of a quantum wire interacting with a lateral two-level quantum dot is presented. The wire conductance is calculated for all different states of charge and spin of the quantum…

Strongly Correlated Electrons · Physics 2007-05-23 Maria A. Davidovich , E. V. Anda , C. A. Busser , G. Chiappe

A small quantum ring with less than 10 electrons was studied by transport spectroscopy. For strong coupling to the leads a Kondo effect is observed and used to characterize the spin structure of the system in a wide range of magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 U. F. Keyser , C. Fuhner , S. Borck , R. J. Haug , M. Bichler , G. Abstreiter , W. Wegscheider

We study a quantum dot connected to the bulk by single-mode junctions at almost perfect conductance. Although the average charge $e\langle N \rangle$ of the dot is not discrete, its spin remains quantized: $s=1/2$ or $s=0$, depending…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 L. I. Glazman , F. W. J. Hekking , A. I. Larkin