Mott insulating state in incommensurate molecular conductors

Seo, Hitoshi; Yoshioka, Hideo*; Otsuka, Yuichi*

We theoretically investigate the possibility of a Mott insulating state in a class of molecular conductors where the composition ratio between two molecular species is incommensurate to each other, i.e., incommensurate molecular conductors. Although the band-filling becomes irrational and then metallic behavior would be expected, the on-site Coulomb repulsion among the valence electrons together with the potential from the closed-shellions supplying the carriers can give rise to an "incommensurate Mott insulator", which is characterized by the carriers being localized with a period incommensurate to the underlying lattice.