Eur. Phys. J. B 32, 49-63 (2003)
https://doi.org/10.1140/epjb/e2003-00073-y

Kondo insulators in the periodic Anderson model: a local moment approach

¹ Oxford University, Physical and Theoretical Chemistry, South Parks Road, Oxford OX1 3QZ, UK
² Department of Physics, I.I. Sc., Bangalore 560 012; and JNCASR, Jakkur, Bangalore 506 064, India

Corresponding author: ^a dlogan@physchem.ox.ac.uk

Received: 19 December 2002
Published online: 14 March 2003

Abstract

The symmetric periodic Anderson model is well known to capture the essential physics of Kondo insulator materials. Within the framework of dynamical mean-field theory, we develop a local moment approach to its single-particle dynamics in the paramagnetic phase. The approach is intrinsically non-perturbative, encompasses all energy scales and interaction strengths, and satisfies the low-energy dictates of Fermi liquid theory. It captures in particular the strong coupling behaviour and exponentially small quasiparticle scales characteristic of the Kondo lattice regime, as well as simple perturbative behaviour in weak coupling. Particular emphasis is naturally given to strong coupling dynamics, where the resultant clean separation of energy scales enables the scaling behaviour of single-particle spectra to be obtained.