相关论文: Bipolaron-SO(5) Non-Fermi Liquid in a Two-channel …
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 a well studied system of a quantum dot coupled to a Coulomb box and leads, realizing a spin-flavor Kondo model. It exhibits a recently discovered non-Fermi liquid (NFL) behavior with emergent SO(5) symmetry. Here, through a…
Non-Fermi liquid (NFL) physics can be realized in quantum dot devices where competing interactions frustrate the exact screening of dot spin or charge degrees of freedom. We show that a standard nanodevice architecture, involving a dot…
It is shown by the Wilson's numerical renormalization-group approach that Non-Fermi liquid (NFL) behaviors arise even for U-impurity with an $f^2$-singlet ground state, and all the puzzling behaviors of R$_{1-x}$U$_x$Ru$_2$Si$_2$ (R=Th, Y…
Hund metals have attracted attention in recent years due to their unconventional superconductivity, which supposedly originates from non-Fermi-liquid (NFL) properties of the normal state. When studying Hund metals using dynamical mean-field…
We reinvestigate the two channel flavor anisotropic model (2CFAK) and one channel compacitified Kondo model (1CCK). For these two models, all the possible fixed points and their symmetries are identified; the finite size spectra, the…
The O(3) symmetric Anderson model is an example of a system which has a stable low energy marginal Fermi liquid fixed point for a certain choice of parameters. It is also exactly equivalent, in the large U limit, to a localized model which…
We investigate the non-Fermi-liquid (NFL) behavior of the impurity Anderson model (IAM) with non-Kramers doublet ground state of the f$^2$ configuration under the tetragonal crystalline electric field (CEF). The low energy spectrum is…
We consider the symmetric single-impurity Anderson model in the presence of pairing fluctuations. In the isotropic limit, the degrees of freedom of the local impurity are separated into hybridizing and non-hybridizing modes. The self-energy…
We study triangular clusters of three spin-1/2 Kondo or Anderson impurities that are coupled to two conduction leads. In the case of Kondo impurities, the model takes the form of an antiferromagnetic Heisenberg ring with Kondo-like exchange…
We discuss the two-channel Kondo problem with a pseudogap density of states, $\rho(\w)\propto|\w|^r$, of the bath fermions. Combining both analytical and numerical renormalization group techniques, we characterize the impurity phases and…
Significant effort has been devoted to the study of "non-Fermi liquid" (NFL) metals: gapless conducting systems that lack a quasiparticle description. One class of NFL metals involves a finite density of fermions interacting with soft order…
To identify what types of non-Fermi liquid (NFL) behavior are most likely to occur in cubic metals due to doublet impurities, we derive every cubic symmetry-allowed, NFL, Kondo-type exchange coupling that does not need accidental degeneracy…
We analyze the particle-hole symmetric two-dimensional Hubbard model on a square lattice starting from weak-to-moderate couplings by means of the field-theoretical renormalization group (RG) approach up to two-loop order. This method is…
We review a recently developed method, based on a pseudoparticle representation of correlated electrons, to describe both Fermi liquid and non-Fermi liquid behavior in quantum impurity systems. The role of the projection onto the physical…
A scaling consideration of the Kondo lattices is performed with account of singularities in the spin excitation spectral function. It is shown that a non-Fermi-liquid (NFL) behavior between two critical values of the bare $s-f$ coupling…
We consider a $SU(N)\times SU(M)$ generalization of the multichannel single-impurity Kondo model which we solve analytically in the limit $N\rightarrow \infty$, $M\rightarrow\infty$, with $\gamma=M/N$ fixed. Non-Fermi liquid behavior of the…
Scaling equations for the Kondo lattice in the paramagnetic and magnetically ordered phases are derived to two-loop order with account of spin dynamics. The results are applied to describe various mechanisms of the non-Fermi-liquid (NFL)…
We investigate a four-impurity Anderson model where localized orbitals are located at vertices of a regular tetrahedron and find a novel fixed point in addition to the ordinary Fermi liquid phase. That is characterized by unscreened scalar…
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…