Related papers: Magnetic impurity in a $U(1)$-Spin Liquid with a S…
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…
Quantum impurity problems in Tomonaga-Luttinger liquids (TLLs) are reviewed with emphasis on their analogy to the Kondo problem in Fermi liquids. First, the problem of a static impurity in a spinless TLL is considered, which is related to…
Quantum spin liquids are topological states of matter that arise in frustrated quantum magnets at low temperatures. At low energies, such states exhibit emergent gauge fields and fractionalized quasiparticles and can also possess enhanced…
We study the Kondo resonance in a spin-1/2 single impurity Anderson model with a gapless conduction band using the equation of motion approach in order to obtain the impurity spectral function. We study two different scenarios for gapless…
We construct an exactly solvable spin-orbital model on a decorated square lattice that realizes an SU(2)-invariant Majorana spin liquid with parton Fermi surfaces, of the kind discussed recently by Biswas et al. [ Phys. Rev. B. {\bf 83},…
Exact results for the thermodynamic properties of ensembles of magnetic impurities with randomly distributed host-impurity couplings in the quantum antiferromagnetic Heisenberg model are presented. Exact calculations are done for arbitrary…
We consider the Fermi polaron problem of an impurity hopping around a two-dimensional square lattice and interacting with a sea of fermions at given filling factor. When the interaction is attractive, we find standard Fermi polaron…
In this paper, a fermionic hierarchical model is defined, inspired by the Kondo model, which describes a 1-dimensional lattice gas of spin-1/2 electrons interacting with a spin-1/2 impurity. This model is proved to be exactly solvable, and…
A fluctuating-valence impurity in a metal is quantum-critical unlike a Kondo impurity which has the properties of a local Fermi-liquid. A systematic theory for the fluctuating-valence lattice is constructed, based on the hybridization and…
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…
A theory of the local magnetic response of a nonmagnetic impurity in a doped antiferromagnet, as relevant to the normal state in cuprates, is presented. It is based on the assumption of the overdamped collective mode in the bulk system and…
The appropriate generalization of the isotropic impurity Anderson model for valence fluctuations between two magnetic multiplets $l^n$ and $l^{n+1}$ is solved in the strong-coupling limit of Wilson's renormalization group for $l\leq$ 3.…
Recent experiments suggest a quantum spin liquid ground state in the material PbCuTe$_2$O$_6$, where $S=1/2$ moments are coupled by antiferromagnetic Heisenberg interactions into a three dimensional structure of corner sharing triangles…
We argue that strongly correlated two dimensional electrons form a spin liquid in some regimes of density and temperature and give the theory of the magnetic properties of this spin liquid using the representation in terms of femions…
In this letter, the Kondo magnetic effect is studied for the $XXZ$ spin chain where the impurities are coupled to the edges of the system. The Hamiltonian of our model can be constructed from the transfer matrix. It is exactly solvable and…
We derive a solvable resonant-level type model, to describe an impurity spin coupled to zero-energy bound states localized at the edge of a one dimensional d-wave superconductor. This results in a two-channel Kondo effect with a quite…
We study an extended SU(N) single-impurity Kondo model in which the impurity spin is described by a combination of Abrikosov fermions and Schwinger bosons. Our aim is to describe both the quasiparticle-like excitations and the locally…
We consider a Kondo-like impurity interacting with fermions on a honeycomb lattice at half-filling, as in the case of graphene. We derive from the lattice model an effective one-dimensional continuum theory which has, in general, four…
We consider a magnetic impurity in the two-dimensional Heisenberg antifferomagnet with long range antiferromagnetic order. At low temperature the impurity magnetic susceptibility has a Curie term ($\propto 1/T$) and a logarithmic correction…
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…