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Related papers: On the Magnetic Nature of Quantum Point Contacts

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We study the formation of local magnetic moments in quantum point contacts. Using a Hubbard-like model to describe point contacts formed in a two dimensional system, we calculate the magnetic moment using the unrestricted Hartree…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. S. Cornaglia , C. A. Balseiro , M. Avignon

Very short quantum wires (quantum contacts) exhibit a conductance structure at a value of conductance close to $0.7 \times 2e^2/h$. It is believed that the structure arises due to the electron-electron interaction, and it is also related to…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 O. P. Sushkov

We consider interaction effects in quantum point contacts on the first quantization plateau, taking into account all non momentum-conserving processes. We compute low-temperature linear and non-linear conductance, shot noise, and…

Mesoscale and Nanoscale Physics · Physics 2007-07-16 Anders Mathias Lunde , Alessandro De Martino , Reinhold Egger , Karsten Flensberg

An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high temperatures. A model accounting for…

Mesoscale and Nanoscale Physics · Physics 2011-01-25 Vincent Thomas Francois Renard , O. A. Tkachenko , V. A. Tkachenko , T. Ota , N. Kumada , J. -C. Portal , Y. Hirayama

Spin-density-functional theory of quantum point contacts (QPCs) reveals the formation of a local moment with a net of one electron spin in the vicinity of the point contact - supporting the recent report of a Kondo effect in a QPC. The…

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

We develop a theoretical model for the description of electron dynamics in coupled quantum wires when the local magnetic moment is formed in one of the wires. We employ a single-particle Hamiltonian that takes account of the specific…

Strongly Correlated Electrons · Physics 2009-11-10 V. I. Puller , L. G. Mourokh , A. Shailos , J. P. Bird

Exchange interaction within a quantum dot strongly affects the transport through it in the Kondo regime. In a striking difference with the results of the conventional model, where this interaction is neglected, here the temperature and…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Pustilnik , L. I. Glazman

We consider electron-electron interaction effects in quantum point contacts on the first quantization plateau, taking into account all scattering processes. We compute the low-temperature linear and nonlinear conductance, shot noise, and…

Mesoscale and Nanoscale Physics · Physics 2009-02-27 A. M. Lunde , A. De Martino , A. Schulz , R. Egger , K. Flensberg

We study the magnetic orbital response of a system of N interacting electrons confined in a two-dimensional geometry and subjected to a perpendicular magnetic field in the finite temperature Hartree-Fock approximation. The electron-electron…

Mesoscale and Nanoscale Physics · Physics 2009-01-23 L. G. G. V. Dias da Silva , Caio H. Lewenkopf , Nelson Studart

We consider transport through a single-molecule magnet strongly coupled to metallic electrodes. We demonstrate that for half-integer spin of the molecule electron- and spin-tunneling \emph{cooperate} to produce both quantum tunneling of the…

Strongly Correlated Electrons · Physics 2009-11-11 C. Romeike , M. R. Wegewijs , W. Hofstetter , H. Schoeller

Very short quantum wires (quantum contacts) exhibit a conductance structure at the value of conductance close to 0.7 x 2e^2/h. The structure was discovered by Thomas et al (Phys. Rev. Lett. {\bf 77}, 135 (1996)). Dependence of the structure…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 O. P. Sushkov

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

In this paper we study the interplay between interference effects in quantum dots (manifested through the appearance of Fano resonances in the conductance), and interactions taken into account in the self-consistent Hartree-Fock…

Mesoscale and Nanoscale Physics · Physics 2011-01-21 Moshe Goldstein , Richard Berkovits

Iron, cobalt and nickel are archetypal ferromagnetic metals. In bulk, electronic conduction in these materials takes place mainly through the $s$ and $p$ electrons, whereas the magnetic moments are mostly in the narrow $d$-electron bands,…

Strongly Correlated Electrons · Physics 2009-06-18 M. R. Calvo , J. Fernández-Rossier , J. J. Palacios , D. Jacob , D. Natelson , C. Untiedt

We report on numerical studies into the interplay of disorder and electron-electron interactions within the integer quantum Hall regime, where the presence of a strong magnetic field and two-dimensional confinement of the electronic system…

Mesoscale and Nanoscale Physics · Physics 2008-01-23 R. A. Römer , C. Sohrmann

In this report, we develop a model for the resonant interaction between a pair of coupled quantum wires, under conditions where self-consistent effects lead to the formation of a local magnetic moment in one of the wires. Our analysis is…

Other Condensed Matter · Physics 2009-11-10 V. I. Puller , L. G. Mourokh , J. P. Bird , Y. Ochiai

We study a small spin-degenerate quantum dot with even number of electrons, weakly connected by point contacts to the metallic electrodes, and subject to an external magnetic field. If the Zeeman energy B is equal to the single-particle…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Pustilnik , Y. Avishai , K. Kikoin

Quantum dots connected to larger systems containing a continuum of states like charge reservoirs allow the theoretical study of many-body effects such as the Coulomb blockade and the Kondo effect. Here, we analyze the nonequilibrium Kondo…

Mesoscale and Nanoscale Physics · Physics 2020-01-31 Levente Máthé , Ioan Grosu

We review the quantum interference effects in a system of interacting electrons confined to a quantum dot. The review starts with a description of an isolated quantum dot. We discuss the status of the Random Matrix theory (RMT) of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 I. L. Aleiner , P. W. Brouwer , L. I. Glazman

The magnetization of quantum dots is discussed in terms of a relatively simple but exactly solvable model Hamiltonian. The model predicts oscillations in spin polarization as a function of dot radius for a fixed electron density. These…

Mesoscale and Nanoscale Physics · Physics 2007-10-11 A. Bansil , D. Nissenbaum , B. Barbiellini , R. Saniz
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