Mean-Field Analysis of Electric Field Effect on Charge Orders in Organic Conductors
Abstract
Description
In order to investigate charge ordering phenomena under electric field, static nonequilibrium Hartree approximation (SNHA) method is formulated on the basis of the nonequilibrium Green's functions introduced by Keldysh. By applying the SNHA to the 3/4-filling extended Hubbard model on anisotropic triangular lattice, we study the stabilities and amplitudes of 3-fold and horizontal charge orders in $θ$ and $θ_d$-(BEDT-TTF)$_2X$ salts under the electric field. The obtained results show that the electric field stabilizes the 3-fold state in comparison to the horizontal state. The amplitude of the 3-fold state tends to decrease by the field, whereas that of the horizontal state does not change.
4pages, 6figures, and 1table
4pages, 6figures, and 1table