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Related papers: Multichannel Kondo impurities in superconductors

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We show through a perturbative and an exact calculation using Wilson's renormalization methods that in the problem of two interacting Kondo impurities, on-site potential scattering generates a quantum-tunneling between the two impurities…

Strongly Correlated Electrons · Physics 2007-05-23 Lijun Zhu , C. M. Varma

We investigate the Kondo effect in two-dimensional disordered electron systems using a finite-temperature quantum Monte Carlo method. Depending on the position of a magnetic impurity, the local moment is screened or unscreened by the spin…

Strongly Correlated Electrons · Physics 2009-11-07 Takuma Ohashi , Sei-ichiro Suga

The Kondo effect and superconductivity are both prime examples of many-body phenomena. Here we report transport measurements on a carbon nanotube quantum dot coupled to superconducting leads that show a delicate interplay between both…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 M. R. Buitelaar , T. Nussbaumer , C. Schoenenberger

We elaborate on the recently introduced concept of reentrant Kondo effect in quantum impurities/dots coupled to hybrid metal-semiconductor contacts [G.~Diniz {\em et al.}, Phys. Rev. B {\bf 101}, 125115 (2020)]. By noticing the equivalence…

Mesoscale and Nanoscale Physics · Physics 2021-08-04 Peter Zalom , Tomáš Novotný

We develop a theoretical framework to study the influences of coupling asymmetry on the thermoelectrics of a strongly coupled SU($N$) Kondo impurity based on a local Fermi liquid theory. Applying non-equilibrium Keldysh formalism, we…

Mesoscale and Nanoscale Physics · Physics 2019-09-25 D. B. Karki , Mikhail N. Kiselev

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

The ordering trend of magnetic impurities at low temperature results in the frustration of the pair-breaking effect and induces a ``recovery'' of superconducting properties. We show that this effect manifests itself in the deviation of the…

Superconductivity · Physics 2015-06-25 A. Bill , S. A. Wolf , Yu. N. Ovchinnikov , V. Z. Kresin

We study the impurity suppression of the critical temperature $T_c$ of the FeAs superconductors theoretically based on the the $\pm$s-wave pairing state of a two band model. The effects of non-magnetic and magnetic impurities are studied…

Superconductivity · Physics 2009-03-07 Yunkyu Bang , Han-Yong Choi , Hyekyung Won

We investigated the doping effects of magnetic and nonmagnetic impurities on the single-crystalline p-type Ba0.5K0.5Fe2-2xM2xAs2 (M = Mn, Ru, Co, Ni, Cu and Zn) superconductors. The superconductivity indicates robustly against impurity of…

We study the influence of anisotropy of the impurity potential on isotope coefficient of an impure superconductor in Born limit. From the isotope coefficient of non-magnetic and magnetic impurities including an angle-resolved Fermi surface…

Superconductivity · Physics 2009-11-11 P. Udomsamuthirun

We study the T=0 Kondo physics of a spin-1/2 impurity in a non-centrosymmetric metal with spin-orbit interaction. Within a simple variational approach we compute ground state properties of the system for an {\it arbitrary} form of…

Strongly Correlated Electrons · Physics 2012-02-23 L. Isaev , D. F. Agterberg , I. Vekhter

The effective spin Hamiltonian of a triple quantum dot with odd electron occupation weakly connected in series with left ($l$) and right ($r$) metal leads is composed of two-channel exchange and co-tunneling terms. Renormalization group…

Strongly Correlated Electrons · Physics 2007-05-23 T. Kuzmenko , K. Kikoin , Y. Avishai

Recently, a series of noncentrosymmetric superconductors has been a subject of considerable interest since the discovery of superconductivity in CePt_3Si. In noncentrosymmetric materials, the degeneracy of bands is lifted in the presence of…

Strongly Correlated Electrons · Physics 2013-01-29 Takashi Yanagisawa

We measure transport through gold grain quantum dots fabricated using electromigration, with magnetic impurities in the leads. A Kondo interaction is observed between dot and leads, but the presence of magnetic impurities results in a…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 H. B. Heersche , Z. de Groot , J. A. Folk , L. P. Kouwenhoven , H. S. J. van der Zant , A. A. Houck , J. Labaziewicz , I. L. Chuang

We study how the multi-channel Kondo effect is dynamically induced to affect the photoemission and the inverse photoemission spectrum when an electron is emitted from (or added to) the completely screened Kondo impurity with spin $S>1/2$.…

Condensed Matter · Physics 2009-10-31 T. Fujii , N. Kawakami

Determining the symmetry of Cooper pairs remains a central challenge in the study of unconventional superconductors, particularly for chiral states that spontaneously break time-reversal symmetry. Here we demonstrate that point-like…

Superconductivity · Physics 2025-07-18 Yuchang Cai , Rui-Xing Zhang

Recent observations of contradictory impurity effect in the heavy-fermion superconductor CeCu2Si2 at ambient pressure have hindered the identification of its pairing symmetry. Here we perform theoretical analyses with both intraband and…

Superconductivity · Physics 2024-08-16 Shan Zhao , Weifu Liu , Yi-feng Yang , Shiping Feng , Bin Liu

We study the effects of random nonmagnetic impurities on superconducting transition temperature $T_c$ in a Cu-doped Bi$_2$Se$_3$, for which four types of pair potentials have been proposed. Although all the candidates belong to $s$-wave…

Superconductivity · Physics 2020-07-22 Takumi Sato , Yasuhiro Asano

We analyze the two Anderson impurity problem, in the strong Coulomb repulsion limit, by means of variational wave functions whose equations we solve analytically. We found two pairs of Doublet states, one odd and one even with respect to…

Strongly Correlated Electrons · Physics 2007-05-23 J. Simonin

We investigate the impurity resonant state induced by non-magnetic impurities in d-wave cuprate superconductors in two different impurity models: (i) in a pure potential scattering model within the T-matrix approach and (ii) in a Bose-Fermi…

Strongly Correlated Electrons · Physics 2009-11-13 Marijana Kircan