Microscopic origin of isotropic non-Heisenberg behavior in highly correlated systems

Autor:	Bastardis, Roland, Guihery, Nathalie, de Graaf, Coen
Rok vydání:	2007
Předmět:	Condensed Matter - Strongly Correlated Electrons
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevB.76.132412
Popis:	We have reanalyzed the microscopic origin of the isotropic deviations that are observed from the energy spacings predicted by the HDVV Hamiltonian. Usually, a biquadratic spin operator is added to the HDVV Hamiltonian to account for such deviations. It is shown here that this operator cannot describe the effect of the excited atomic non-Hund states which brought the most important contribution to the deviations. For systems containing more than two magnetic centers, non-Hund states cause additional interactions that are of the same order of magnitude as the biquadratic exchange and should have significant effects on the macroscopic properties of extended systems. Comment: 4 pages, 3 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/0706.3353 Zobrazit plný text záznamu View this record from Arxiv