Related papers: Overscreened Kondo fixed point in S=1 spin liquid
The underscreened Kondo effect is studied within a model of two impurities S=1 interacting with the conduction band and via an interimpurity coupling $K\vec{S_1}.\vec{S_2}$. Using a mean-field treatment of the bosonized Hamiltonian, we show…
We solve the problem of a magnetic impurity coupled to a U(1) quantum spin liquid with spinon Fermi surface and compute the impurity spectral function. Using the slave rotor mean field approach combined with gauge field fluctuations, we…
A spin-1/2 magnetic impurity coupled to a one-dimensional correlated electron system have been studied by applying the density renormalization group method. The Kondo temperature is substantially enhanced by strong repulsive interactions in…
Due to the separation between the spin and the orbital screening scales, the normal state of Hund's metals at ambient temperature can be loosely characterized as a partially coherent state with fluctuating spins and quenched orbital…
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…
We propose a new approach to the Kondo lattice in order to describe simultaneously the Kondo effect and the local magnetism. This approach relies on an original representation of the $S=1/2$ impurity spin in which the different degrees of…
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…
We construct models of excitations about a Fermi surface that display calculable deviations from Fermi liquid behavior in the low-energy limit. They arise as a consequence of coupling to a Chern-Simons gauge field, whose fluctations are…
A Kondo model for three spin-one-half impurities placed at the vertices of an equilateral triangle is studied using the numerical renormalization-group method. The impurity spins can form two frustrated doublets which, because of the…
The single impurity Kondo problem in the one-dimensional $\delta$-potential Fermi gas is exactly solved for two sets of special coupling constants via Bethe ansatz. It is found that ferromagnetic Kondo screening does occur in one case which…
We study a generalization of the Kondo model in which the impurity spin is represented by Abrikosov fermions in a rotation group SU(P) larger than the SU(N) group associated to the spin of the conduction electrons, thereby forcing the…
A brief review is given of a new method for studying the critical behavior of quantum impurity problems, based on conformal field theory techniques, which I developed with Andreas Ludwig. Some results on the overscreened Kondo problem are…
We investigate the entanglement properties of a Kondo system undergoing a transition to a state with a quenched magnetic impurity, using the density matrix renormalization group (DMRG) method. We focus on a two-channel spin-1 Kondo impurity…
Tunnelling impurities in metals have been known for some time to have the potential for exhibiting Kondo-like physics. However previous models based on an impurity hopping between two equivalent positions have run into trouble due to the…
A magnetic impurity with a larger $S=1$ spin remains partially screened by the Kondo effect when embedded in a metal. However, when placed within an $s$-wave superconductor, the interplay between the superconducting energy gap $\Delta$ and…
We investigate the quantum transport through Kondo impurity assuming both a large number of orbital channels $\mathcal K$$\gg $$1$ for the itinerant electrons and a semi-classical spin ${\cal S}$ $\gg $ $1$ for the impurity. The non-Fermi…
Using numerical renormalization group techniques, we study static and dynamic properties of a family of single-channel Kondo impurity models with axial magnetic anisotropy $DS_z^2$ terms; such models are appropriate to describe magnetic…
The Kondo effect in a Tomonaga-Luttinger liquid ($U<<t$) is studied by using the non-Abelian bosonization. The $q=2k_F$ enhanced spin fluctuations generate a special Kondo effect, for any sign of the exchange coupling $J_K$…
A multipolar Kondo model of an impurity spin S_I=3/2 interacting with conduction electrons with spin s_c=3/2 is investigated using boundary conformal field theory. A two-channel Kondo (2CK) -like non-Fermi liquid (NFL) under the…
We investigate the Kondo effect of a spin-3/2 Fermi gas and give a detailed calculation of the impurity resistance and ground state energy based on the s-d exchange model. It is found that the impurity resistance increases logarithmically…