Charge Ordering and Spin gap in NaV_2O_5
arXiv:cond-mat/9805185 · doi:10.1016/S0022-3697(99)00056-6
Abstract
A possible ground state of NaV_2O_5 is proposed based on the Hartree approximation for both on-site and intersite Coulomb interactions. The results indicate that the intersite Coulomb interaction induces a zigzag type of charge disproportionation (i.e. charge ordering) along the ladders of V-ions resulting in the localized spins between neighboring ladders to form a spin gap. This new state, which is different from the spin-Peierls state so far believed, seems to be consistent with the existing experimental results.
3 pages, 4 figures, submitted to J. Phys. Soc. Jpn