Related papers: Kondo Effect in a Spin-3/2 Fermi Gas
The electrical resistivity including the Kondo resistivity increase at low temperature is calculated for thin films of dilute magnetic alloys. Assuming that in the non-magnetic host the spin-orbit interaction is strong like in Au and Cu,…
We consider an impurity problem in a quasi-two-dimensional Fermi gas, where a spin-down impurity is immersed in a Fermi sea of N spin-up atoms. Using a variational approach and an effective two-channel model, we obtain the energies of the…
We study the low-temperature behavior of a magnetic impurity which is weakly coupled to correlated conduction electrons. To account for conduction electron interactions a diagrammatic approach in the frame of the 1/N expansion is developed.…
The La dilution of the Kondo lattice CeCoIn_5 is studied. The scaling laws found for the magnetic susceptibility and the specific heat reveal two well-separated energy scales, corresponding to the single impurity Kondo temperature T_K and…
The Kondo effect in quantum dots (QDs) - artificial magnetic impurities - attached to ferromagnetic leads is studied with the numerical renormalization group (NRG) method. It is shown that the QD level is spin-split due to presence of…
We discuss the role of many-body spin correlations in nonlinear optical response of a Fermi sea system with a deep impurity level. Due to the Hubbard repulsion between electrons at the impurity, the optical transitions between the impurity…
Paramagnetic impurities in a quantum spin-liquid can result in Kondo effects with highly unusual properties. We have studied the effect of locally exchange-coupling a paramagnetic impurity with the spin-1/2 honeycomb Kitaev model in its…
We investigate theoretically the linear conductance of a two-level quantum dot as a function of the gate voltage and different strength of coupling to the external electronic system (the reservoir). Apart from the weak coupling regime,…
In the strong coupling limit, an effective resonant level model is derived for the spin-1 underscreened Kondo impurity model. A local quantum critical behavior is induced by the formation of a bound state with partially screened magnetic…
The variant of the single-impurity Kondo problem in which the conduction-band density of states has a power-law pseudogap at the Fermi energy is known to exhibit a zero-temperature phase transition at a finite exchange coupling. The…
We study how the non-Fermi-liquid nature of the overscreened multi-channel Kondo impurity model affects the response to a BCS pairing term that, in the absence of the impurity, opens a gap $\Delta$. We find that non-Fermi liquid features do…
The effect of a magnetic field on the spectral density of a $\rm{S=1/2}$ Kondo impurity is investigated at zero and finite temperatures by using Wilson's numerical renormalization group method. A splitting of the total spectral density is…
The Kondo effect of a single magnetic impurity embedded in the Lieb lattice is studied by the numerical renormalization group. When the band flatness is present in the local density of states, it quenches the participation of all dispersive…
We consider a magnetic impurity coupled to both fermionic quasiparticles with a pseudogap density of states and bosonic spin fluctuations. Using renormalization group and large-N calculations we investigate the phase diagram of the…
The Kondo effect in a Luttinger liquid is studied using the renormalization group method. By renormalizing the boson fields, scaling equations to the second order for an arbitrary Luttinger interaction are obtained. For the ferromagnetic…
We investigate the one-dimensional Kondo lattice model (1D KLM) for ferromagnetic Kondo couplings. The so-called ferromagnetic 2-leg spin ladder and the S=1 antiferromagnet occur as new one-dimensional Kondo insulators. Both exhibit a spin…
The (111) surface of Cu, Ag and Au is characterized by a band of surface Shockley states, with constant density of states beginning slightly below the Fermi energy. These states as well as bulk states hybridize with magnetic impurities…
Stimulated by anomalous behaviors found in non-Kramers $f$-electron systems in an applied magnetic field, we study a two-channel Kondo lattice model by using a cluster extension of the dynamical mean-field theory combined with the…
We consider the Kondo effect arising from a hydrogen impurity in graphene. As a first approximation, the strong covalent bond to a carbon atom removes that carbon atom without breaking the $C_{3}$ rotation symmetry, and we only retain the…
We study a spin S=M/2--Kondo system coupled to electrons in an arbitrary nonequilibrium situation above Kondo temperature. Coupling to hot electrons leads to an increased inverse lifetime of pseudo particles, related to the Korringa width.…