Related papers: Overscreened Kondo fixed point in S=1 spin liquid
We address the problem of a magnetic impurity in a two dimensional $U(1)$ spin liquid where the spinons have gap-less excitations near the Fermi-surface and are coupled to an emergent gap-less gauge field. Using a large N expansion we…
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 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…
The Kondo problem, which describes the interaction of a spin $s$ magnetic impurity with a free Fermi gas, is a classic example of strongly coupled physics. Historically, the problem has been solved by Wilson's numerical renormalization…
We consider the single channel Kondo problem with the Kondo coupling between a spin $S$ impurity and conduction electrons with spin $j$. These problems arise as multicritical points in the parameter spaces of two- and higher-level tunneling…
We study a generalized multichannel single-impurity Kondo model, in which the impurity spin is described by a representation of the SU(N) group which combines bosonic and fermionic degrees of freedom. The impurity spin states are described…
The feasibility of realizing overscreened Kondo effect in ultra-cold Fermi gas of atoms with spin $s \ge \tfrac{3}{2}$ in the presence of a localized magnetic impurity atom is proved realistic. Specifying to a system of ultra cold $^{22}$Na…
We consider the spatial spin correlations around a partially screened spin-1 magnetic moment in a metal exhibiting the underscreened Kondo effect. We find that the underscreening of the impurity spin results in spatial spin correlations…
The Kondo effect, an eminent manifestation of many-body physics in condensed matter, is traditionally explained as exchange scattering of conduction electrons on a spinful impurity in a metal. The resulting screening of the impurity's local…
The multichannel Kondo model with SU(N) spin symmetry and SU(K) channel symmetry is considered. The impurity spin is chosen to transform as an antisymmetric representation of SU(N), corresponding to a fixed number of Abrikosov fermions…
A novel large-N limit of the multichannel Kondo model is introduced, for representations of the impurity spin described by Schwinger bosons. Three cases are found, associated with underscreening, overscreening and exact Kondo screening of…
We study the Kondo effect of spin-1/2 magnetic impurities in gapped Z2 spin liquids on two-dimensional lattices. We find that if the impurity is placed at a high-symmetry location, a nontrivial spinon fractionalization class of the impurity…
The problem of a spin-1/2 magnetic impurity near an antiferromagnetic transition of the host lattice is solved. The problem is shown to transform to a multichannel problem. A variety of fixed points is discovered asymptotically near the…
We study the breakdown of Kondo screening by a local magnetic field from the perspective of a measurement-driven entanglement transition in a monitored quantum system. Here, the Kondo coupling leads to the growth in entanglement of an…
Thermodynamic properties are presented for four magnetic impurity models describing delocalized fermions scattering from a localized orbital at an energy-dependent rate $\Gamma(\epsilon)$ which vanishes precisely at the Fermi level,…
The compact U(1) gauge field occurs in many fractionalized descriptions of low dimensional quantum magnetism and heavy fermion systems. In this respect a fundamental question about the gauge field is whether it is confined or not in the…
We study odd-membered chains of spin-(1/2) impurities, with each end connected to its own metallic lead. For antiferromagnetic exchange coupling, universal two-channel Kondo (2CK) physics is shown to arise at low energies. Two overscreening…
We study the spin thermopower in the two-channel spin-1/2 Kondo model which exhibits the phenomenon of impurity spin overscreening and non-Fermi-liquid properties. While magnetic field lower than the Kondo temperature does not strongly…
We consider the non-Fermi liquid quantum critical state of the spin-S two-impurity Kondo model, and its potential realization in a quantum dot device. Using conformal field theory (CFT) and the numerical renormalization group (NRG), we show…
Using the Schwinger boson spin representation, we reveal a new aspect to the physics of a partially screened magnetic moment in a metal, as described by the spin $S$ Kondo model. We show that the residual ferromagnetic interaction between a…