Incommensurate antiferromagnetic state in off-1/2-filled system -ETHg(=Br,Cl)

Seo, Hitoshi; Yoshioka, Hideo*

Two-dimensional molecular conductors -ETHg(=Br,Cl) have incommensurate composition, which are attracting interest as a system with 10-20% hole-doped compared with -ET. At high presure, the systems show metal-insulator transition, where the possibility of "incommensurate Mott insulator" is discussed. In this work, we investigate the -type Hubbard model including the incommensurate potential due to the anions, within mean-field approximation. We find that when the anion potential and the on-site Coulomb repulsion exceed critical values, an insulating state with incommensurate charge and spin ordering is stabilized.