Abstract
We study the Anderson lattice model with one orbital per lattice site as the simplest model which describes generic features of heavy fermion materials. The resistivity and magnetic susceptibility results obtained within dynamical mean-field theory (DMFT) for a nearly half-filled conduction band show the existence of a single energy scale which is similar to the single-ion Kondo temperature . To determine the importance of intersite correlations, we have also solved the model within cellular DMFT (CDMFT) with two sites in a unit cell. The antiferromagnetic region on the phase diagram is much narrower than in the single-site solution, having a smaller critical hybridization and Néel temperature . At temperatures above the nonlocal correlations are small, and the DMFT paramagnetic solution is in this case practically exact, which justifies the ab initio local density approximation (LDA) + DMFT approach in theoretical studies of heavy fermions. Strong intersite correlations in the CDMFT solution for , however, indicate that they have to be properly treated in order to unravel the physical properties near the quantum critical point.
2 More- Received 23 June 2011
DOI:https://doi.org/10.1103/PhysRevB.84.115105
©2011 American Physical Society