Related papers: Selection Rules for Two Channel Kondo Models of U …
We present studies of a simple Anderson model Hamiltonian for Ce$^{3+}$ ions in cubic symmetry with three configurations ($f^0$,$f^1$,$f^2$). Our Hamiltonian includes: (i) One-channel Anderson model; (ii) Two-channel Anderson model. Using…
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.…
When a magnetic ion vibrates in a metal, it inevitably introduces a new channel of hybridization with conduction electrons and in general, the vibrating ion induces electric dipole moment. In such a situation, we find that magnetic and…
We investigate the mixed-valent regime of a two-configuration Anderson impurity model for uranium ions, with separate quadrupolar and magnetic doublets. With a new Monte Carlo approach and the non-crossing approximation we find: (i) A…
We derive the coupling of a localized hexadecapolar mode to conduction electrons in tetragonal symmetry. The derivation can be easily adapted to arbitrary multipoles in arbitrary environment. We relate our model to the two-channel Kondo…
We consider the Kondo effect in Y-junctions of anisotropic XY models in an applied magnetic field along the critical lines characterized by a gapless excitation spectrum. We find that, while the boundary interaction Hamiltonian describing…
On the basis of an idea of the electron-hole relation between $f^2$ and $f^4$ states in a $j$-$j$ coupling scheme, we point out a possibility that two-channel Kondo phenomena can be observed even in cubic transuranium compounds including Np…
The effective spin Hamiltonian of a triple quantum dot with odd electron occupation weakly connected in series with left ($l$) and right ($r$) metal leads is composed of two-channel exchange and co-tunneling terms. Renormalization group…
The magnetic properties of the two-channel periodic Anderson model for uranium ions, comprised of a quadrupolar and a magnetic doublet are investigated through the crossover from the mixed-valent to the stable moment regime using dynamical…
We discuss Kondo phenomena in a seven-orbital impurity Anderson model hybridized with $\Gamma_8$ conduction electrons by employing a numerical renormalization group method. In particular, we focus on the case with three local $f$ electrons,…
To discuss Kondo effects of a magnetic ion vibrating in the sea of conduction electrons, a generalized Anderson model is derived. The model includes a new channel of hybridization associated with phonon emission or absorption. In the…
The unusual electronic and magnetic properties of the systems Ce$_3$Pd$_{20}$T$_6$ (T = Ge, Si) with two non-equivalent Ce positions are discussed. The logarithmic growth of resistance for both the systems confirms the presence of the Kondo…
We clarify the two-channel Kondo effect in the seven-orbital Anderson model hybridized with $\Gamma_8$ conduction electrons by employing a numerical renormalization group method.From the numerical analysis for the case with two local $f$…
Strong electron correlations have long been recognized as driving the emergence of novel phases of matter. A well recognized example is high-temperature superconductivity which cannot be understood in terms of the standard weak-coupling…
We illustrate the emergence of the three-channel Kondo effect in a seven-orbital impurity Anderson model hybridized with $\Gamma_7$ and $\Gamma_8$ conduction electron bands employing a numerical renormalization group method. In particular,…
Dynamical tunneling systems have been proposed earlier to display a two-channel Kondo effect, the orbital index of the particle playing the role of a pseudospin in the equivalent Kondo problem, and the spin being a silent channel index.…
In non-Kramers Kondo systems with a quadrupolar degrees of freedom, an ordinary magnetic Kondo effect can compete with the quadrupolar Kondo effect. We discuss such competition keeping Pr$T_{2}$Zn$_{20}$ ($T$=Ir, Rh) and Pr$T_{2}$Al$_{20}$…
A scenario for the formation of symmetry protected non-Fermi-liquid (NFL) Kondo effect (KE) with spin variable enumerating Kondo channels is suggested and worked out. In doubly occupied symmetric triple quantum dot within parallel geometry,…
The recent detailed study of quasi-one-dimensional iron-based ladders, with the $3d$ iron electronic density $n = 6$, has unveiled surprises, such as orbital-selective phases. However, similar studies for $n=6$ iron chains are still rare.…
We show that electron correlations lead to a bad metallic state in chalcogenides FeSe and FeTe despite the intermediate value of the Hubbard repulsion $U$ and Hund's rule coupling $J$. The evolution of the quasi particle weight $Z$ as a…