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Related papers: Ferromagnetic Kondo Effect at Nanocontacts

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We investigate the quantum phase transition of itinerant ferromagnets. It is shown that correlation effects in the underlying itinerant electron system lead to singularities in the order parameter field theory that result in an effective…

Statistical Mechanics · Physics 2017-09-27 Thomas Vojta , D. Belitz , T. R. Kirkpatrick , R. Narayanan

We propose a scheme to realize the Kondo model with tunable anisotropy using alkaline-earth atoms in an optical lattice. The new feature of our setup is Floquet engineering of interactions using time-dependent Zeeman shifts, that can be…

Magnetic impurities embedded in a metal are screened by the Kondo effect, signaled by the formation of an extended correlation cloud, the so-called Kondo or screening cloud. In a superconductor, the Kondo state turns into sub-gap…

Strongly Correlated Electrons · Physics 2022-01-04 Cătălin Paşcu Moca , Ireneusz Weymann , Miklós Antal Werner , Gergely Zaránd

To discuss Kondo effects of a magnetic ion vibrating in the sea of conduction electrons, a generalized Anderson model is derived. The model includes a new channel of hybridization associated with phonon emission or absorption. In the…

Strongly Correlated Electrons · Physics 2015-05-27 Satoshi Yashiki , Shunsuke Kirino , Kazumasa Hattori , Kazuo Ueda

We carefully consider the interplay between ferromagnetism and the Kondo screening effect in the conventional Kondo lattice systems at finite temperatures. Within an effective mean-field theory for small conduction electron densities, a…

Strongly Correlated Electrons · Physics 2013-04-12 Yu Liu , Guang-Ming Zhang , Lu Yu

The problem of a spin-1/2 magnetic impurity near an antiferromagnetic transition of the host lattice is solved. The problem is shown to transform to a multichannel problem. A variety of fixed points is discovered asymptotically near the…

Strongly Correlated Electrons · Physics 2007-05-23 H. Maebashi , K. Miyake , C. M. Varma

We investigate the spin Seebeck effect and spin pumping in a junction between a ferromagnetic insulator and a magnetic impurity deposited on a normal metal. By the numerical renormalization group calculation, we show that spin current is…

Mesoscale and Nanoscale Physics · Physics 2021-09-15 Tsuyoshi Yamamoto , Takeo Kato , Mamoru Matsuo

We address the quantum transition of a spin-1/2 antiferromagnetic Kondo lattice model with an easy-axis anisotropy using the extended dynamical mean field theory. We derive results in real frequency using the bosonic numerical…

Strongly Correlated Electrons · Physics 2009-11-11 Jian-Xin Zhu , Stefan Kirchner , Ralf Bulla , Qimiao Si

The feasibility of realizing overscreened Kondo effect in ultra-cold Fermi gas of atoms with spin $s \ge \tfrac{3}{2}$ in the presence of a localized magnetic impurity atom is proved realistic. Specifying to a system of ultra cold $^{22}$Na…

Quantum Gases · Physics 2015-05-06 I. Kuzmenko , T. Kuzmenko , Y. Avishai , K. Kikoin

Fermionic atoms in an optical superlattice can realize a very peculiar Anderson lattice model in which impurities interact with each other through a discretized set of delocalized levels. We investigate the interplay between Kondo effect…

Condensed Matter · Physics 2013-05-29 B. Paredes , C. Tejedor , J. I. Cirac

We have studied the effect of anisotropies on the quantum phase transition of the Kondo necklace model in dimensions D=1, 2 and 3. Both the anisotropy $\delta$ of the inter-site interaction term and anisotropy $\Delta$ of the on-site Kondo…

Strongly Correlated Electrons · Physics 2009-11-11 A. Langari , P. Thalmeier

We study the spin-1 chain with nearest neighbor couplings that are rotationally invariant, but include both Heisenberg and biquadratic exchange, with random strengths. We demonstrate, using perturbative renormalization group methods as well…

Condensed Matter · Physics 2009-10-30 Kun Yang , R. N. Bhatt

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

I consider models with an impurity spin coupled to a fluctuating gaussian field with or without additional Kondo coupling of the conventional sort. In the case of isotropic fluctuations, the renormalisation group flows for these models have…

Strongly Correlated Electrons · Physics 2008-02-03 Anirvan M. Sengupta

In a single state of a quantum dot the Kondo effect arises due to the spin-degeneracy, which is present if the dot is occupied with one electron (N = 1). The eigenstates of a carbon nanotube quantum dot possess an additional orbital…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 B. Babic , T. Kontos , C. Schoenenberger

We study the Kondo effect in the electron transport through a quantum dot coupled to ferromagnetic leads, using a real-time diagrammatic technique which provides a systematic description of the nonequilibrium dynamics of a system with…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yasuhiro Utsumi , Jan Martinek , Gerd Schön , Hiroshi Imamura , Sadamichi Maekawa

In metals containing magnetic impurities, conduction electrons screen the magnetic impurities and induce the Kondo effect, i.e., the enhancement of the electrical resistance at low temperatures. Motivated by recent advances in manipulating…

Strongly Correlated Electrons · Physics 2024-08-02 Jun Mochida , Yuto Ashida

The interaction of a lattice of localized magnetic moments with a sea of conduction electrons in Kondo lattice models induces rich quantum phases of matter, such as Fermi liquids with heavily renormalized electronic quasiparticles, quantum…

We investigated the typical time scales of the Kondo correlations formation for the single-state Anderson model, when coupling to the reservoir is switched on at the initial time moment. The influence of the Kondo effect appearance on the…

Mesoscale and Nanoscale Physics · Physics 2017-01-31 N. S. Maslova , P. I. Arseyev , V. N. Mantsevich

Progress in the fabrication of nanometer-scale electronic devices is opening new opportunities to uncover the deepest aspects of the Kondo effect, one of the paradigmatic phenomena in the physics of strongly correlated electrons. Artificial…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Pablo Jarillo-Herrero , Jing Kong , Herre S. J. van der Zant , Cees Dekker , Leo P. Kouwenhoven , Silvano De Franceschi