Effect of nearest neighbor repulsion on the low frequency phase diagram of a quarter-filled Hubbard-Holstein chain

Philippe Maurel (1) , Marie-Bernadette Lepetit (1)

1 LPQ - Laboratoire de Physique Quantique

We have studied the influence of nearest-neighbor (NN) repulsion on the low frequency phase diagram of a quarter-filled Hubbard-Holstein chain. The NN repulsion term induces the apparition of two new long range ordered phases (one $4k_F$ CDW for positive $U_{eff} = U-2g^2/\\omega$ and one $2k_F$ CDW for negative $U_{eff}$) that did not exist in the V=0 phase diagram. These results are put into perspective with the newly observed charge ordered phases in organic conductors and an interpretation of their origin in terms of electron-molecular vibration coupling is suggested.

Mots clés: t-J model; electron-phonon coupling; spin chains

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

Philippe Maurel, Marie-Bernadette Lepetit. Effect of nearest neighbor repulsion on the low frequency phase diagram of a quarter-filled Hubbard-Holstein chain. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2002, 66, pp.075117. ⟨hal-00003050⟩