We present exact results for a diatomic molecule described by the Ansderson model which includes both on-site and intersite hybridization, as well as the on-site Coulomb repulsion between f- and conduction electrons (the Falicov-Kimball term). The mixed valence behaviour is demonstrated in the subspace with N = 2 electrons, while the competition between Kondo screening and RKKY interaction is investigated for N = 4 electrons. The Falicov-Kimball term restricts the range of stability of the mixed valence state, and increases the values of the Kondo temperature and of the crossover temperature to disordered f-moments in the Kondo and RKKY regime, respectively, while it increases the temperature above which the ferromagnetic correlations between f-moments are destabilized for N = 3 electrons. © 1995.
A molecular model for strongly correlated electron systems
LUBRITTO, Carmine;
1995
Abstract
We present exact results for a diatomic molecule described by the Ansderson model which includes both on-site and intersite hybridization, as well as the on-site Coulomb repulsion between f- and conduction electrons (the Falicov-Kimball term). The mixed valence behaviour is demonstrated in the subspace with N = 2 electrons, while the competition between Kondo screening and RKKY interaction is investigated for N = 4 electrons. The Falicov-Kimball term restricts the range of stability of the mixed valence state, and increases the values of the Kondo temperature and of the crossover temperature to disordered f-moments in the Kondo and RKKY regime, respectively, while it increases the temperature above which the ferromagnetic correlations between f-moments are destabilized for N = 3 electrons. © 1995.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
