PHASE-DIAGRAM OF THE ONE-DIMENSIONAL HOLSTEIN MODEL OF SPINLESS FERMIONS

The one-dimensional Holstein model of spinless fermions interacting wi th dispersionless phonons is studied using a new variant of the densit y matrix renormalization group. By examining various low-energy excita tions of finite chains, the metal-insulator phase boundary is determin ed precisely and agrees with the predictions of strong coupling theory in the antiadiabatic regime and is consistent with renormalization gr oup arguments in the adiabatic regime. The Luttinger liquid parameters , determined by finite-size scaling, are consistent with a Kosterlitz- Thouless transition.