Isospin model for suppression of charge order in hole- doped NaV_2O_5

Abstract

The layered perovskite compound NaV_2O_5 exhibits charge ordering (CO) and spin gap formation which is driven by inter- site Coulomb forces and exchange dimerisation. Experimentally it was found that the CO transition is rapidly reduced by doping. Charge ordering in NaV_2O_5 has a quasi 1D character due to inter- ladder frustration in the Trellis lattice. Based on an extended pseudospin (T=1) approach for hole doped NaV_2O_5 ladders we construct an Ising like model that explains qualitatively the destruction of the CO phase as function of hole doping δand show how the CO parameter depends on δand the ratio of Coulomb and hopping energies.

6 pages, 4 figures

References in corpus (4)

• Low-Temperature Structure of the Quarter-Filled Ladder Compound alpha'-NaV2O5
• Structure determination, valence, and superexchange in the dimerized low temperature phase of alpha'-NaV2O5
• A microscopic model for the structural transition and spin gap formation in alpha'-NaV2O5
• Exact diagonalisation study of charge order in the quarter-filled two-leg ladder system NaV2O5