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We investigate the linear and nonlinear dc transport through an interacting quantum dot connected to two ferromagnetic electrodes around Kondo regime with spin-flip scattering in the dot. Using a slave-boson mean field approach for the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Jing Ma , 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

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 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

We study the linear conductance through a double-quantum-dot system consisting of an interacting dot in its Kondo regime and an effectively noninteracting dot, connected in parallel to metallic leads. Signatures in the zero-bias conductance…

Mesoscale and Nanoscale Physics · Physics 2008-10-13 Luis G. Dias da Silva , Kevin Ingersent , Nancy Sandler , Sergio Ulloa

We study the interaction corrections to the transport coefficients in open quantum dots (i.e. dots connected to leads of large conductance $G \gg e^2/\pi\hbar$), via a quantum kinetic equation approach. The effects of all the channels of…

Mesoscale and Nanoscale Physics · Physics 2008-09-25 Y. Ahmadian , G. Catelani , I. L. Aleiner

Thermoelectric transport phenomena in a single-level quantum dot coupled to ferromagnetic leads are considered theoretically in the Kondo regime. The dot is described by the Anderson model with Rashba type spin-orbit interaction. The…

Mesoscale and Nanoscale Physics · Physics 2014-12-10 Łukasz Karwacki , Piotr Trocha , Józef Barnaś

Using Wilson's numerical renormalization group (NRG) technique we compute zero-bias conductance and various correlation functions of a double quantum dot (DQD) system. We present different regimes within a phase diagram of the DQD system.…

Strongly Correlated Electrons · Physics 2007-06-01 Rok Zitko Janez Bonca

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

Quantum entanglement between an impurity spin and electrons nearby is a key property of the single-channel Kondo effects. We show that the entanglement can be detected by measuring electron conductance through a double quantum dot in an…

Mesoscale and Nanoscale Physics · Physics 2018-08-29 Gwangsu Yoo , Seung-Sup B. Lee , H. -S. Sim

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

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

The Kondo effect of a Co atom on Cu(100) was investigated with a low-temperature scanning tunneling microscope using a monoatomically sharp nickel tip. Upon a tip-Co contact, the differential conductance spectra exhibit a spin-split…

Mesoscale and Nanoscale Physics · Physics 2016-10-17 D. -J. Choi , S. Guissart , M. Ormaza , N. Bachellier , O. Bengone , P. Simon , L. Limot

We report on the phase measurements on a quantum dot containing a single electron in the Kondo regime. Transport takes place through a single orbital state. Although the conductance is far from the unitary limit, we measure for the first…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 M. Zaffalon , Aveek Bid , M. Heiblum , D. Mahalu , V. Umansky

The conductance G of a pair of single-channel point contacts in series, one of which is a spin filter, increases from 1/2 to 2/3 x e^2/h with more and more spin-flip scattering. This excess conductance was observed in a quantum dot by…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 C. W. J. Beenakker

One dimensional (1D) quantum wires exhibit a conductance feature near 0.7 x 2e^2/h in connection with many-body interactions involving the electron spin. With the possibility of exploiting this effect for novel spintronic device…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 D. J. Reilly

We analyze the zero temperature conductance of a parallel T-shaped double quantum dot system. We present an analytical expression for the conductance of the system in terms of the total number of electrons in both quantum dots. Our results…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 M. Crisan , I. Grosu , I. Tifrea

In this paper we analyze transport through a double dot system connected to two external leads. Imagining each dot possessing a single active level, we model the system through a generalization of the Anderson model. We argue that this…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Robert M. Konik

We study the Kondo effect and related transport properties in orbitally degenerate vertical quantum dot systems with plural electrons. Applying the non-crossing approximation to the three-orbital Anderson impurity model with the finite…

Strongly Correlated Electrons · Physics 2008-09-10 Tomoko Kita , Rui Sakano , Takuma Ohashi , Sei-ichiro Suga

For unpolarized electrons in a clean quantum wire, density functional theory reveals a thermally activated suppression of conductance. The activation temperature T_A grows slowly (roughly quadratically) with gate voltage due to pinning of…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Kenji Hirose , Ned S. Wingreen