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The interplay between the Kondo effect and the inter-dot magnetic interaction in a coupled-dot system is studied. An exact result for the transport properties at zero temperature is obtained by diagonalizing a cluster, composed by the…

Strongly Correlated Electrons · Physics 2009-10-31 C. A. Büsser , E. V. Anda , A. L Lima , Maria A. Davidovich , G. Chiappe

We consider 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 a smooth crossover between…

Mesoscale and Nanoscale Physics · Physics 2007-10-24 A. L. Chudnovskiy , Frank Hellmuth , V. Kagalovsky

The effective interaction between magnetic impurities in metals that can lead to various magnetic ground states often competes with a tendency for electrons near impurities to screen the local moment (Kondo effect). The simplest system…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 N. J. Craig , J. M. Taylor , E. A. Lester , C. M. Marcus , M. P. Hanson , A. C. Gossard

Equilibrium transport properties of a single-level quantum dot tunnel-coupled to ferromagnetic leads and exchange-coupled to a side nonmagnetic reservoir are analyzed theoretically in the Kondo regime. The equilibrium spectral functions and…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Ireneusz Weymann , Jozef Barnas

We investigate parametric pumping of a spin-polarized current through a nearly-closed quantum dot in a perpendicular magnetic field. Pumping is achieved by tuning the tunnel couplings to the left and right lead - thereby operating the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 M. Blaauboer , C. M. L. Fricot

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

We theoretically examine generation of spin-polarized current using multi-terminated quantum dot with spin-orbit interaction. First, a two-level quantum dot is analyzed as a minimal model, which is connected to $N$ ($\ge 2$) external leads…

Mesoscale and Nanoscale Physics · Physics 2012-11-12 Tomohiro Yokoyama , Mikio Eto

We show theoretically that a strongly spin-polarized current can be generated in semiconductors by taking advantage of the ferromagnetic phase of a quantum dot array (QDA). A Hubbard model with coupling to leads is used to study the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 David M. -T. Kuo , Y. -C. Chang

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

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 study an orbitally degenerate Kondo effect in a triangular triple quantum dot (TTQD), where the three dots are connected vertically with a single metallic lead through electron tunneling. Both spin and orbital degrees of freedom play an…

Mesoscale and Nanoscale Physics · Physics 2016-05-20 Mikito Koga , Masashige Matsumoto , Hiroaki Kusunose

We propose a spin polarizer device composed of a quantum dot connected to the spin polarized leads. The spin control of the current flowing through the device is entirely due to the Coulomb interactions present inside the dot. We show that…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Piotr Stefanski

We investigate the effects of spin-polarized leads on the Kondo physics of a quantum dot using the numerical renormalization group method. Our study demonstrates in an unambiguous way that the Kondo effect is not necessarily suppressed by…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Mahn-Soo Choi , David Sanchez , Rosa Lopez

A new type of Kondo effect peculiar to unconventional superconductors is studied theoretically by using the Wilson's numerical renormalization group method. In this case, an angular momentum of a Cooper pair plays an important role in the…

Superconductivity · Physics 2009-11-07 Masashige Matsumoto , Mikito Koga

Non-equilibrium Green's function technique has been used to calculate spin-dependent electronic transport through a quantum dot in the Kondo regime. The dot is described by the Anderson Hamiltonian and is coupled either symmetrically or…

Other Condensed Matter · Physics 2009-11-11 R. Swirkowicz , M. Wilczynski , J. Barnas

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

An unpolarized charge current passing through a chaotic quantum dot with spin-orbit coupling can produce a spin polarized exit current without magnetic fields or ferromagnets. We use random matrix theory to estimate the typical spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jacob J. Krich , Bertrand I. Halperin

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 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 arises from many-body interactions between localized magnetic impurities and conduction electrons, affecting electronic properties at low temperatures. In this study, we investigate the Kondo effect within a two-dimensional…

Strongly Correlated Electrons · Physics 2025-09-30 T. O. Puel , M. A. Manya , G. S. Diniz , E. Vernek , G. B. Martins