Effectiveaction approach to strongly correlated fermion systems
Abstract
We construct a functional for the singleparticle Green's function, which is a variant of the standard BaymKadanoff functional. The stability of the stationary solutions to the functional is directly related to aspects of the irreducible particle hole interaction through the BetheSalpeter equation. A startling aspect of this functional is that it allows a simple and rigorous derivation of both the standard and extended dynamical meanfield (DMFT) equations as stationary conditions. Though the DMFT equations were formerly obtained only in the limit of infinite lattice coordination, the functional described in the work presents a way of directly extending DMFT to finitedimensional systems, both on a lattice and in a continuum. Instabilities of the stationary solution at the bifurcation point of the functional signal the appearance of a zero mode at the Mott transition which then couples to physical quantities resulting in divergences at the transition.
 Publication:

Physical Review B
 Pub Date:
 March 2001
 DOI:
 10.1103/PhysRevB.63.115110
 arXiv:
 arXiv:condmat/9911223
 Bibcode:
 2001PhRvB..63k5110C
 Keywords:

 71.27.+a;
 Strongly correlated electron systems;
 heavy fermions;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 9 pages