Edge States in Molecular Solid α-(BEDT-TTF)2I3: Effects of Electron Correlations

We examine the edge states of the Dirac electrons in the molecular material \alpha-(BEDT-TTF)2I3 with electron-electron interactions. Based on the analysis of the extended Hubbard model with the Hartree-Fock approximation, we show that the charge-ordered phase has the gapless edge states only in the vicinity of the phase boundary between the zero-gap state and the charge-ordered phase. We also show a peculiar flux phase caused by the long-range Coulomb interaction with the same mechanism as topological Mott insulator phase.