Abstract
It is proved that the ground state of the half-filled Kondo lattice is unique and spin singlet. For a wide class of the systems including extra interactions with various topology of the lattice structure, this proof is generalized and the total spin of the ground state is determined. A ferromagnetic ground state appears in some special cases and its criterion is given.
DOI:https://doi.org/10.1103/PhysRevB.55.3042
©1997 American Physical Society