Related papers: Solution of the two impurity, two channel Kondo Mo…
Several Quantum Impurity problems with four flavors of bulk fermions have zero temperature fixed points that show non fermi liquid behavior. They include the two channel Kondo effect, the two impurity Kondo model, and the fixed point…
The bosonization of the $S=1/2$ anisotropic two-channel Kondo model is shown to yield two equivalent representations of the original problem. In a straight forward extension of the Emery-Kivelson approach, the interacting resonant level…
We study the interplay between the spin-liquid and Kondo physics, as related to the non-magnetic part of the phase diagram of heavy fermion materials. Within the unrestricted mean-field treatment of the infinite-$U$ 2D Anderson-Heisenberg…
The finite-size spectrum for the multi-channel Kondo model is derived analytically from the exact solution, by mapping the nontrivial Z$_{n}$ part of the Kondo scattering into that for the RSOS model coupled with the impurity. The analysis…
We study the problem of a boundary magnetic impurity coupled with the solvable $t-J$ chains. Our model provides a good start point to understand the Kondo problem in a Luttinger liquid as well as in a strongly correlated host. The Kondo…
I construct non-Fermi liquid (NFL) quantum impurity models that are similar to the overscreened multi-channel Kondo models with the difference that an odd number of electron species screen the impurity. The simplest of them, named…
We give a brief review of the Kondo effect and exactly solve the nonequilibrium Kondo problem at the special point in the parameter space of the model with spin-dependent chemical potentials. Using the obtained solution, we compute several…
We predict experimentally accessible signatures for helical Majorana fermions in a topological superconductor by coupling to two quantum dots in the local moment regime (corresponding to spin-$1/2$ impurities). Taking into account RKKY…
When the ground state of a localized ion is a non-Kramers doublet, such localized ions may carry multipolar moments. For example, Pr$^{3+}$ ions in a cubic environment would possess quadrupolar and octupolar, but no magnetic dipole,…
A Coulomb blockaded $M$-Majorana island coupled to normal metal leads realizes a novel type of Kondo effect where the effective impurity "spin" transforms under the orthogonal group $SO(M)$. The impurity spin stems from the non-local…
We apply the recently developed extremely correlated Fermi liquid theory to the Anderson impurity model, in the extreme correlation limit. We develop an expansion in a parameter \lambda, related to n_d, the average occupation of the…
We introduce a model for Ce$^{3+}$ impurities in cubic metals which exhibits competition between the Fermi-liquid fixed point of the single channel Kondo model and the non-Fermi-liquid fixed point of the two- and three-channel Kondo models.…
We have studied the antiferromagnetic quantum phase transition of a 2D Kondo-Heisenberg square lattice using the non-linear sigma model. A renormalization group analysis of the competing Kondo -- RKKY interaction was carried out to 1-loop…
We calculate the dynamical spin response of Kondo impurity and Kondo lattice systems within a semiphenomenological Fermi liquid description, at low temperatures $T<T_K$, the Kondo temperature, and low magnetic fields $B \ll k_B T_K/g\mu_B$.…
We study by NRG the spectral properties of a two-orbital Anderson impurity model in the presence of an exchange splitting which follows either regular or inverted Hund's rules. The phase diagram contains a non-Fermi liquid fixed point…
In order to study the interplay between Kondo and Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, we calculate the spin-spin correlation functions between two Kondo impurities coupled to different sites of a half-filled open Hubbard…
In this work, a quantum dot couples to two helical edge states of a 2D topological insulator through weak tunnelings is studied. We show that if the electron interactions on the edge states are repulsive, with Luttinger liquid parameter $ K…
The cooperative behavior of quantum impurities on 2D materials, such as graphene and bilayer graphene, is characterized by a non-trivial competition between screening (Kondo effect), and Ruderman-Kittel-Kasuya-Yosida (RKKY) magnetism. In…
We use the numerical renormalization group method to study an Anderson impurity in a conduction band with the density of states varying as rho(omega) \propto |omega|^r with r>0. We find two different fixed points: a local-moment fixed point…
We consider the motion of a spin-1/2 impurity in a one-dimensional gas of spin-1/2 fermions. For antiferromagnetic interaction between the impurity and the fermions, the low temperature behavior of the system is governed by the two-channel…