Speakers: Jindřich Kolorenč (Department of Condensed Matter Theory, Institute of Physics ASCR)
Place: Na Slovance, main lecture hall
Presented in English
Organisers:
Department of Condensed Matter Theory
Abstract: We study how a spin-1/2 Anderson impurity model responds to a static homogeneous magnetic field using the variational method of Gunnarsson and Schoenhammer. We confine our investigation to the so-called local-moment regime in the limit of infinite Coulomb repulsion at the impurity orbital. We evaluate the magnetic polarization induced at the impurity as well as the total polarization of the surrounding conduction electrons. These two magnetizations are antiparallel which indicates (some) cancellation of the impurity magnetic moment by the conduction-electron spins. Nevertheless, the polarization of the conduction electrons turns out to be much smaller than the polarization at the impurity and hence the concept of a cloud of conduction electrons that would screen the local moment, which is occasionally promoted in the literature, does not appear as an accurate representation of the mechanism responsible for quenching the magnetism in the Anderson impurity model.
Copyright © 2008-2010, Fyzikální ústav AV ČR, v. v. i.
