Kondo insulators modeled by the one-dimensional Anderson lattice: A numerical-renormalization-group study
- Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92717 (United States)
In order to better understand Kondo insulators, we have studied both the symmetric and asymmetric Anderson lattices at half filling in one dimension using the density-matrix formulation of the numerical renormalization group. The asymmetric case is treated in the mixed-valence regime. We have calculated the charge gap, the spin gap, and the quasiparticle gap as a function of the repulsive interaction {ital U} using open boundary conditions for lattices as large as 24 sites. We find that the charge gap is larger than the spin gap for all {ital U} for both the symmetric and asymmetric cases. Ruderman-Kittel-Kasuya-Yosida interactions are evident in the {ital f}-spin--{ital f}-spin correlation functions at large {ital U} in the symmetric case, but are suppressed in the asymmetric case as the {ital f} level approaches the Fermi energy. This suppression can also be seen in the staggered susceptibility {chi}({ital q}=2{ital k}{sub {ital F}}) and it is consistent with neutron scattering measurements of {chi}({ital q}) in CeNiSn.
- OSTI ID:
- 44606
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 51, Issue 16; Other Information: PBD: 15 Apr 1995
- Country of Publication:
- United States
- Language:
- English
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