Effect of Anion Lattice on SDW States in Quarter-Filled Organic Conductors

Abstract

The ground state and collective modes of spin density wave (SDW) states with a quarter-filled band are examined in the presence of a two-fold periodic potential which originates in the anion lattice of organic conductors. The competition between the potential, W 0 , and the commensurability energy results in the coexistence of the 2 k F -SDW and the 4 k F -CDW (charge density wave) and the reduction of an excitation gap for the longitudinal mode. The W 0 -dependence of the gap is examined in terms of a phase Hamiltonian.