Eur. Phys. J. B 75, 497-504 (2010)
https://doi.org/10.1140/epjb/e2010-00140-4

Density of states in the magnetic ground state of the Friedel-Anderson impurity

Department of Physics, University of Southern California, Los Angeles, 90089-0484 California, USA

Corresponding author: ^a bergmann@physics.usc.edu

Received: 17 February 2009
Revised: 14 February 2010
Published online: 12 May 2010

Abstract

By applying a magnetic field whose Zeeman energy exceeds the Kondo energy by an order of magnitude the ground state of the Friedel-Anderson impurity is a magnetic state. In recent years the author introduced the FAIR (Friedel Artificially Inserted Resonance) method to investigate the impurity properties. Within this FAIR approach the full excitation spectrum and the composition of the excitations is calculated and numerically evaluated. From the excitation spectrum the electron density of states is calculated. Majority and minority d-resonances are obtained. The width of the resonances is about twice as wide as the mean field theory predicts. This broadening reduces the height of the resonance curve and therefore the density of states by a factor of two. This yields an intuitive understanding for a previous result of the FAIR approach that it requires a much larger Coulomb interaction for the formation of a magnetic moment than the mean field theory.