Charge order in the incommensurate compounds $Sr_{14-x}Ca_xCu_{24}O_{41}$

Marie-Bernadette Lepetit (1, 2) , Alain Gellé (1)

1 LPQ - Laboratoire de Physique Quantique
2 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

The present paper studies, using ab-initio calculations, the influence of the incommensurate structural modulations on the low energy physics of the $Sr_{14-x}Ca_xCu_{24}O_{41}$ oxides. On-site, nearest-neighbor and next-nearest-neighbor effective parameters were computed within a $t-J+V$ model based on the copper magnetic orbitals. The structural modulations appear to be the key degree of freedom, responsible for the low energy properties such as the electron localization, the formation of dimers in the $x=0$ compound or the anti-ferromagnetic order in the $x=13.6$ compound.

Mots clés: Ab-initio electronic calculation; incommensurate compounds; low dimensional systems

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Marie-Bernadette Lepetit, Alain Gellé. Charge order in the incommensurate compounds $Sr_{14-x}Ca_xCu_{24}O_{41}$. Physica B: Condensed Matter, 2005, 359-361, pp.1258. ⟨hal-00004149⟩