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Related papers: Underscreened Kondo effect in quantum dots coupled…

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In this paper, we investigate the electronic transport properties of a quantum dot (QD) connected to two ferromagnetic leads and one superconductor lead in the Kondo regime by means of the finite-$U$ slave boson mean field approach and…

Mesoscale and Nanoscale Physics · Physics 2020-01-08 C. Lee , Bing Dong , X. L. Lei

We report Kondo-like behaviour in a quantum antidot (a submicron depleted region in a two-dimensional electron gas) in the quantum-Hall regime. When both spin branches of the lowest Landau level encircle the antidot in a magnetic field…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 M. Kataoka , C. J. B. Ford , M. Y. Simmons , D. A. Ritchie

We report a strong Kondo effect (Kondo temperature ~ 4K) at high magnetic field in a selective area growth semiconductor quantum dot. The Kondo effect is ascribed to a singlet-triplet transition in the ground state of the dot. At the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 W. G. van der Wiel , S. De Franceschi , J. M. Elzerman , S. Tarucha , L. P. Kouwenhoven , J. Motohisa , F. Nakajima , T. Fukui

A quantum dot coupled to ferromagnetically polarized one-dimensional leads is studied numerically using the density matrix renormalization group method. Several real space properties and the local density of states at the dot are computed.…

Strongly Correlated Electrons · Physics 2007-05-23 C. J. Gazza , M. E. Torio , J. A. Riera

Conductance, on-site and inter-site charge fluctuations and spin correlations in the system of two side-coupled quantum dots are calculated using the Wilson's numerical renormalization group (NRG) technique. We also show spectral density…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Rok Zitko , Janez Bonca

We systematically investigate electron transport through double quantum dots with particular emphasis on interference induced via multiple paths of electron propagation. By means of the slave-boson mean-field approximation, we calculate the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yoichi Tanaka , Norio Kawakami

Over-screened Kondo effect is feasible in carbon nanotube quantum dot junction hosting a spin $\tfrac{1}{2}$ atom with single $s$-wave valence electron (e.g Au). The idea is to use the two valleys as two symmetry protected flavor quantum…

Strongly Correlated Electrons · Physics 2014-08-22 Igor Kuzmenko , Tetyana Kuzmenko , Yshai Avishai

We present the first quantitative experimental evidence for the underscreened Kondo effect, an uncomplete compensation of a quantized magnetic moment by conduction electrons, as originally proposed by Nozieres and Blandin. The device…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Nicolas Roch , Serge Florens , Theo A. Costi , Wolfgang Wernsdorfer , Franck Balestro

While the properties of the Kondo model in equilibrium are very well understood, much less is known for Kondo systems out of equilibrium. We study the properties of a quantum dot in the Kondo regime, when a large bias voltage V and/or a…

Strongly Correlated Electrons · Physics 2009-11-10 A. Rosch , J. Paaske , J. Kroha , P. Wölfle

We study the transport properties of a quantum dot coupled to a normal and a superconducting lead. The dot is represented by a generalized Anderson model. Correlation effects are taken into account by an appropriate self-energy which…

Strongly Correlated Electrons · Physics 2009-10-31 J. C. Cuevas , A. Levy Yeyati , A. Martin-Rodero

We study numerically and analytically the dynamical (AC) conductance through a two-dot system, where only one of the dots is coupled to the leads but it is also side-coupled to the other dot through an antiferromagnetic exchange (RKKY)…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Chung-Hou Chung , Gergely Zarand , Peter Wölfle

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 study transport through a quantum dot coupled to normal and superconducting leads using the numerical renormalization group method. We show that the low-energy properties of the system are described by the local Fermi liquid theory…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yoichi Tanaka , Norio Kawakami , Akira Oguri

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 investigate the effects induced by spin polarization in the contacts attached to a serial double quantum dot. The polarization generates effective magnetic fields and suppresses the Kondo effect in each dot. The super-exchange…

Mesoscale and Nanoscale Physics · Physics 2012-06-14 Rok Žitko , Jong Soo Lim , Rosa Lopez , Jan Martinek , Pascal Simon

Motivated by recent STM experiments, we explore the magnetic field induced Kondo effect that takes place at symmetry protected level crossings in finite Co adatom chains. We argue that the effective two-level system realized at a level…

Strongly Correlated Electrons · Physics 2019-10-30 Bimla Danu , Fakher Assaad , Frédéric Mila

We study transport through two quantum dots coupled by an RKKY interaction as a function of temperature and magnetic field. By applying the Numerical Renormalization Group (NRG) method we obtain the transmission and the linear conductance.…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Chung-Hou Chung , Walter Hofstetter

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

The low temperature electrical conductance through correlated quantum dots provides a sensitive probe of the physics (e.g., of Fermi-liquid vs non-Fermi-liquid behavior) of such systems. Here, we investigate the role of level asymmetry…

Strongly Correlated Electrons · Physics 2013-04-29 L. Merker , S. Kirchner , E. Muñoz , T. A. Costi

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