Metal-insulator transition in dirty Kondo insulators

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.362014· OSTI ID:280090

Schlottmann, P; Hellberg, C S ^[1]

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1. Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)

We consider arbitrary clusters of Kondo holes in a Kondo insulator described by the nondegenerate symmetric Anderson lattice with a nearest-neighbor tight-binding conduction band on a simple cubic lattice. The {ital f}-electron self energy is considered within the local approximation. Each Kondo hole introduces a boundstate in the gap. The quantum interference in the scattering off the impurities gives rise to interactions among the Kondo holes. The spectral weight of the bound states is predominantly localized on the sites neighboring the Kondo holes. Clusters of impurities separated by more than one lattice site are disconnected for boundstates at the Fermi level. On a simple cubic lattice the metal-insulator transition in the impurity band then reduces to the site percolation of Kondo holes with first, second and fourth nearest neighbors. We use the low density mean cluster size expansion and a small cell renormalization to estimate the critical concentration. Hopping in the conduction band beyond nearest neighbors reduces the percolation threshold. Hence, 9.9{percent} of Kondo holes is an upper bound for the insulator to become a metal. {copyright} {ital 1996 American Institute of Physics.}

• OSTI ID: 280090
• Report Number(s): CONF-951101--
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 79; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BOUND STATE
ELECTRIC CONDUCTIVITY
ELECTRON-IMPURITY INTERACTIONS
ELECTRONIC STRUCTURE
FERMI LEVEL
FREQUENCY DEPENDENCE
IMPURITIES
KONDO EFFECT
METAL-INSULATOR TRANSFORMATIONS
SEMICONDUCTOR MATERIALS
TEMPERATURE DEPENDENCE