相关论文: Two-Impurity Anderson model in an Antiferromagneti…
We investigate the effects of magnetic impurities in a superconducting state with $s_\pm$ pairing symmetry. Within a two-band model, we find that the intra-band magnetic scattering serves as a pair breaker while the inter-band magnetic…
In conventional s-wave superconductors, only magnetic impurities exhibit impurity bound states, whereas for an s+- order parameter they can occur for both magnetic and non-magnetic impurities. Impurity bound states in superconductors can…
We study ferromagnetic transition in three-dimensional double-exchange model containing impurities. The influence of both spin fluctuations and impurity potential on conduction electrons is described in coherent potential approximation. In…
Motivated by experiments on ion irradiated graphene, we compute the resistivity of graphene with dilute impurities. In the local moment regime we employ the perturbation theory up to third order in the exchange coupling to determine the…
By introducing a normal self-energy to incorporate the effects of magnetic impurities, Kondo effects in single-walled metallic carbon nanotubes are investigated within the Anderson model and Landauer formula. Magnetic impurities induce…
We investigate the effect that Rashba spin-orbit coupling has on the low energy behaviour of a two dimensional magnetic impurity system. It is shown that the Kondo effect, the screening of the magnetic impurity at temperatures T < T_K, is…
Magnetic impurity effects on metallic carbon nanotubes are studied theoretically. The resolvent method for the multi channel Kondo effect is applied to the band structure of the kp perturbation hamiltonian in the limit of the infinite…
The two dimensional Hubbard model in the presence of diagonal and off-diagonal disorder is studied at half filling with a finite temperature quantum Monte Carlo method. Magnetic correlations as well as the electronic compressibility are…
We consider a localized impurity atom that interacts with a cloud of fermions in the paired state. We develop an effective scattering length description of the interaction between an impurity and a fermionic atom using their vacuum…
A magnetic moment in a metal or in a quantum dot is, at low temperatures, screened by the conduction electrons through the mechanism of the Kondo effect. This gives rise to spin-spin correlations between the magnetic moment and the…
A single Anderson impurity model recently predicted, through its unstable fixed point, the phase diagram of a two band model correlated conductor, well confirmed by Dynamical Mean Field Theory in infinite dimensions. We study here the one…
In several experiments the magnitude of the contribution of magnetic impurities to the Kondo resistivity shows size dependence in mesoscopic samples. It was suggested ten years ago that magnetic surface anisotropy can be responsible for the…
The localization length, $\xi$, in a 2--dimensional Anderson insulator depends on the electron spin scattering rate by magnetic impurities, $\tau_s^{-1}$. For antiferromagnetic sign of the exchange, %constant, the time $\tau_s$ is {\em…
Based on the tight-binding formalism, we investigate the Anderson and the Kondo model for an adaom magnetic impurity above graphene. Different impurity positions are analyzed. Employing a partial wave representation we study the nature of…
We present a mapping of correlated multi-impurity Anderson models to a cluster model coupled to a number of effective conduction bands capturing its essential low-energy physics. The major ingredient is the complex single-particle self…
A Coqblin-Schrieffer impurity of spin $S$ coupled to the boundary of an open SU(N)-invariant $t-J$ chain with $N = 2S+2$ is studied. The model is integrable as a function of one coupling parameter $v$ for arbitrary spin and band filling.…
By using a model Hamiltonian with d-wave superconductivity and competing antiferromagnetic (AF) orders, the local staggered magnetization distribution due to nonmagnetic impurities in cuprate superconductors is investigated. From this, the…
Experiments on (Ga,Mn)As in the low-doping insulating phase have shown evidence for the presence of an impurity band at 110 meV above the valence band. The motivation of this paper is to investigate the role of the impurity band in…
Using numerical techniques we study the zero temperature properties of a substitutional magnetic impurity in a one-dimensional correlated system described by the Hubbard model with repulsive interaction $U$. We find that, while the static…
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…