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Related papers: Orbital Kondo effect in double quantum dots

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Spin and charge transport through a quantum dot coupled to external nonmagnetic leads is analyzed theoretically in terms of the non-equilibrium Green function formalism based on the equation of motion method. The dot is assumed to be…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 R. Swirkowicz , J. Barnas , M. Wilczynski

We study the non-equilibrium regime of the Kondo effect in a quantum dot laterally coupled to a narrow wire. We observe a split Kondo resonance when a finite bias voltage is imposed across the wire. The splitting is attributed to the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. De Franceschi , R. Hanson , W. G. van der Wiel , J. M. Elzerman , J. J. Wijpkema , T. Fujisawa , S. Tarucha , L. P. Kouwenhoven

We consider a `quantum dot' in the Coulomb blockade regime, subject to an arbitrarily large source-drain voltage V. When V is small, quantum dots with odd electron occupation display the Kondo effect, giving rise to enhanced conductance.…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 P. Coleman , C. Hooley , Y. Avishai , Y. Goldin , A. F. Ho

We demonstrate a tunable Kondo effect realized in small quantum dots. We can switch our dot from a Kondo impurity to a non-Kondo system as the number of electrons on the dot is changed from odd to even. We show that the Kondo temperature…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Sara M. Cronenwett , Tjerk H. Oosterkamp , Leo P. Kouwenhoven

In this paper we study the thermopower of a quantum dot connected to two leads in the presence of Kondo correlation by employing a modified second-order perturbation scheme at nonequilibrium. A simple scheme, Ng's ansatz [Phys. Rev. Lett.…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Bing Dong , X. L. Lei

We consider the Kondo effect in quantum dots coupled to Luttinger liquid leads, focussing on the case of repulsive interactions and spin SU(2) symmetry in the leads. We find that the system can flow to the 1-channel or 2-channel Kondo fixed…

Strongly Correlated Electrons · Physics 2007-05-23 Eugene H. Kim

We study the Kondo effect in a quantum dot coupled to half-metallic ferromagnetic electrodes in the regime of strong on-dot correlations. Using the equation of motion technique for nonequilibrium Green functions in the slave boson…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mariusz Krawiec

We investigate the effects of spin-orbit interaction (SOI) on the exchange cotunneling through a spinful Coulomb blockaded quantum dot. In the case of zero magnetic field, Kondo effect is shown to take place via a Kramers doublet and the…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 J. Paaske , A. Andersen , K. Flensberg

The Kondo effect and the Fano-Kondo effect are important phenomena that have been observed in quantum dots (QDs). We theoretically investigate the transport properties of a coupled QD system in order to study the possibility of detecting a…

Strongly Correlated Electrons · Physics 2013-05-09 Tetsufumi Tanamoto , Yu-xi Liu , Xuedong Hu , Franco Nori

We study the Kondo effect in multiple-dot systems for which the inter- as well as intra-dot Coulomb repulsions are strong, and the inter-dot tunneling is small. The application of the Ward-Takahashi identity to the inter-dot dynamical…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Rui Sakano , Norio Kawakami

We analyze the transport properties of a double quantum dot device in the side-coupled configuration. A small quantum dot (QD), having a single relevant electronic level, is coupled to source and drain electrodes. A larger QD, whose…

Mesoscale and Nanoscale Physics · Physics 2014-03-12 J. A. Andrade , Pablo S. Cornaglia , A. A. Aligia

We consider the spin and orbital Kondo effect in a parallel arrangement of two strongly electrostatically coupled quantum dots. Increasing the exchange of electrons between the dots through the attached leads induces the transition between…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 A. L. Chudnovskiy

We present a general description of low temperature transport through a quantum dot with any number of electrons at filling factor $1<\nu <2$. We provide a general description of a novel Kondo effect which is turned on by application of an…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 C. Tejedor , L. Martin-Moreno

We study the Kondo effect of a two-orbital vertical quantum dot (QD) coupled to two ferromagnetic leads by employing an equation of motion method. When the ferromagnetic leads are coupled with parallel spin polarization, we find three peaks…

Strongly Correlated Electrons · Physics 2011-04-19 Hitoshi Yoshizumi , Kensuke Inaba , Tomoko Kita , Sei-ichiro Suga

Numerical analysis of the simplest odd-numbered system of coupled quantum dots reveals an interplay between magnetic ordering, charge fluctuations and the tendency of itinerant electrons in the leads to screen magnetic moments. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 R. Zitko , J. Bonca , A. Ramsak , T. Rejec

We propose that two-channel orbital Kondo ``spin'' 1/2 conductance can be measured in a quantum dot at Coulomb Blockade with an odd number of electrons with contacts in a pillar configuration, if an orthogonal magnetic field induces an…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Domenico Giuliano , Benoit Jouault , Arturo Tagliacozzo

The out-of-equilibrium transport properties of a double quantum dot system in the Kondo regime are studied theoretically by means of a two-impurity Anderson hamiltonian with interimpurity hopping. The hamiltonian is solved by means of a…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Ramon Aguado , David C. Langreth

We investigate low-temperature transport characteristics of a side-coupled double quantum dot where only one of the dots is directly connected to the leads. We observe Fano resonances, which arise from interference between discrete levels…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 S. Sasaki , H. Tamura , T. Akazaki , T. Fujisawa

Spin-polarized transport through a quantum dot strongly coupled to ferromagnetic electrodes with non-collinear magnetic moments is analyzed theoretically in terms of the non-equilibrium Green function formalism. Electrons in the dot are…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 R. Swirkowicz , M. Wilczynski , J. Barnas

We investigate the transport through a nanoscale device consisting of a degenerate double-orbital Anderson dot coupled to two uncorrelated leads. We determine the thermoelectric transport properties close to the one-electron regime and…

Mesoscale and Nanoscale Physics · Physics 2012-08-06 J. Azema , A. -M. Daré , S. Schäfer , P. Lombardo