Interpolation solution of the single-impurity Anderson model

Noncrossing approximation solution of the anisotropic Anderson impurity model

The thermodynamic and magnetic properties of a single impurity Anderson model that describes Ce in an environment with hexagonal symmetry is treated within the noncrossing approximation. It is found that the properties of the system at temperatures larger than the crystal field splitting are described by a Kondo temperature of the sixfold-degenerate spin-orbit multiplet and at low temperatures ...

The asymmetric single - impurity Anderson model – the modified perturbation theory

——————————————————————————————————————— Abstract We investigate the single-impurity Anderson model by means of the recently introduced modified perturbation theory. This approximation scheme yields reasonable results away from the symmetric case. The agreement with exactly known results for the symmetric case is checked, and results for the non-symmetric case are presented. With decreasing cond...

Size and dimensionality effect in single-impurity Anderson model

Compact approximate solution to the Friedel-Anderson impurity problem

An approximate ground state of the Anderson-Friedel impurity problem is presented in a very compact form. It requires solely the optimization of two localized electron states and consists of four Slater states Slater determinants . The resulting singlet ground-state energy lies far below the Anderson mean-field solution and agrees well with the numerical results by Gunnarsson and Schönhammer, w...

Spectral Density of the Two-Impurity Anderson Model

We investigate static and dynamical ground-state properties of the twoimpurity Anderson model at half filling in the limit of vanishing impurity separation using the dynamical density-matrix renormalization group method. In the weakcoupling regime, we find a quantum phase transition as function of inter-impurity hopping driven by the charge degrees of freedom. For large values of the local Coul...