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Related papers: Kondo effect in a two-level quantum dot coupled to…

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We analyze the equilibrium transport properties of underscreened Kondo effect in the case of a two-level quantum dot coupled to ferromagnetic leads. Using the numerical renormalization group (NRG) method, we have determined the gate voltage…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Ireneusz Weymann , Laszlo Borda

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

The Kondo effect in coupled quantum dots is investigated from the viewpoint of transmission spectroscopy using the slave-boson formalism of the Anderson model. The antiferromagnetic spin-spin coupling $J$ between the dots is taken into…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Tomosuke Aono , Mikio Eto

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

Orbital Kondo effect in a system of two single-level quantum dots attached to external electron reservoirs is considered theoretically. The dots are coupled via direct hoping term and Coulomb interaction. The Kondo temperature is evaluated…

Mesoscale and Nanoscale Physics · Physics 2010-09-28 Piotr Trocha

Electron tunneling through a double quantum dot molecule side attached to a quantum wire, in the Kondo regime, is studied. The mean-field finite-U slave-boson formalism is used to obtain the solution of the problem. We found conductance…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Gustavo A. Lara , Pedro A. Orellana , J. Yanez , Enrique V. Anda

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

We study the Kondo and transport properties of a quantum dot with a single magnetic Mn ion connected to metallic leads. By employing a numerical renormalization group technique we show that depending on the value of ferromagnetic coupling…

Mesoscale and Nanoscale Physics · Physics 2011-10-04 E. vernek , Fanyao Qu , F. M. Souza , J. C. Egues , E. V. Anda

We investigate the equilibrium and out-of-equilibrium Kondo effects in a single-level interacting quantum dot connected to two ferromagnetic leads. Within the non-crossing approximation, we calculate the total density of states (DOS), the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Bing Dong , H. L. Cui , S. Y. Liu , X. L. Lei

We investigate a symmetrical double quantum dot system serially attached to the leads. The emphasis is on the numerical analysis of finite inter-dot tunneling in the presence of inter-dot repulsive capacitive coupling. The results reveal…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Jernej Mravlje , Anton Ramsak , Tomaz Rejec

We investigate a lateral semiconductor quantum dot with a large number of electrons in the limit of strong coupling to the leads. A Kondo effect is observed and can be tuned in a perpendicular magnetic field. This Kondo effect does not…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 C. Fuhner , U. F. Keyser , R. J. Haug , D. Reuter , A. D. Wieck

We develop a general method to evaluate the Kondo temperature in a multilevel quantum dot that is weakly coupled to conducting leads. Our theory reveals that the Kondo temperature is strongly enhanced when the intradot energy-level spacing…

Strongly Correlated Electrons · Physics 2015-05-20 Ion Garate , Ian Affleck

We theoretically study enhancement mechanisms of the Kondo effect in multilevel quantum dots. In quantum dots fabricated on semiconductors, the energy difference between discrete levels \Delta is tunable by applying a magnetic field. With…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Mikio Eto

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

We consider a lateral double-dot system in the Coulomb blockade regime with a single spin-1/2 on each dot, mutually coupled by an anti-ferromagnetic exchange interaction. Each of the two dots is contacted by two leads. We demonstrate that…

Strongly Correlated Electrons · Physics 2007-08-06 V. Koerting , P. Wölfle , J. Paaske

Using exact-diagonalization techniques supplemented by a Dyson equation embedding procedure, the transport properties of multilevel quantum dots are investigated in the Kondo regime. The conductance can be decomposed into the contributions…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 C. A. Büsser , G. B. Martins , K. A. Al-Hassanieh , Adriana Moreo , Elbio Dagotto

The non-Fermi-liquid properties of an ultrasmall quantum dot coupled to a lead and to a quantum box are investigated. Tuning the ratio of the tunneling amplitudes to the lead and box, we find a line of two-channel Kondo fixed points for…

Strongly Correlated Electrons · Physics 2007-05-23 Frithjof B. Anders , Eran Lebanon , Avraham Schiller

A detailed study of the low-temperature physics of an interacting double quantum dot system in a T-shape configuration is presented. Each quantum dot is modeled by a single Anderson impurity and we include an inter-dot electron-electron…

Mesoscale and Nanoscale Physics · Physics 2013-03-05 Irisnei L. Ferreira , P. A. Orellana , G. B. Martins , F. M. Souza , E. Vernek

Using a laterally-fabricated quantum-dot (QD) spin-valve device, we experimentally study the Kondo effect in the electron transport through a semiconductor QD with an odd number of electrons (N). In a parallel magnetic configuration of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 K. Hamaya , M. Kitabatake , K. Shibata , M. Jung , M. Kawamura , K. Hirakawa , T. Machida , T. Taniyama , S. Ishida , Y. Arakawa

Properties of the Kondo effect in quantum dots depend sensitively on the coupling parameters and so on the realization of the quantum dot -- the Kondo temperature itself becomes a mesoscopic quantity. Assuming chaotic dynamics in the dot,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 R. K. Kaul , Denis Ullmo , Harold U. Baranger