Collective Modes of SDW with One-Dimensional Quarter-Filled Band

Abstract

Fluctuations of both charge density and spin density around the mean-fields of the spin density wave (SDW) state have been studied by calculating collective modes inthe case of one-dimensional quarter-filled band and arbitrary magnitude of the inter-action. It is shown that the coexistence of the 2k_F-SDW with the 4k_F-charge densitywave is crucial for the commensurability energy and the collective mode of the density fluctuation.