Resistivity of the Kondo lattice

Abstract

The electrical resistivity of the Kondo lattice is studied within the model of Lacroix and Cyrot (79): in this model, the Kondo interaction is transformed into a fictitious s-f hybridisation Jx/2. In order to describe the transport properties, the authors must go beyond a mean field theory and introduce the thermal fluctuations of the hybridisation x. At high temperatures (above T_k), the system may be treated as a collection of incoherent Kondo impurities. The resistivity, evaluated within the phase shift method exhibits a logarithmic decrease as expected. At low temperature, coherence develops between impurities and the system is really a Kondo lattice. Spatial fluctuations (from site to site) of the s-f hybridisation are considered as being responsible for the electron scattering. The resistivity depends strongly on the conduction electron number n: the authors find for n1 approximately (1-n)^1/3 T_K; for n=1 the resistivity is that of a semiconductor with p approximately exp(T_K/T).