Stability of the Kondo lattice in the large-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>N</mml:mi></mml:math>limit

Abstract

We consider a Kondo lattice of rare-earth ions, as a description of materials such as YbCuAl and $\ensuremath{\alpha}$-Ce, by an expansion in $\frac{1}{N}$, where $N=2j+1$. We show that in the large-$N$ limit the nonmagnetic state is stable against magnetic order and that its susceptibility and specific heat are those of an ensemble of isolated impurities.