Charge Transfer Instability with Structural Change. II. Mean Field Theory for One-Dimensional N-Sites N-Electrons System

Abstract

Stable and metastable phases of a one-dimensional many-electron system with short range electron-electron (e-e) repulsion and site-diagonal electron-phonon (e-p) interaction are studied within the mean field theory and in the adiabatic limit. The total energy of the system is calculated as a function of the three parameters: the transfer energy of the electron between neighbouring two sites T , the on-site e-e repulsive energy U and the e-p coupling energy S . The resultant phase diagram is such that the “ T - U - S triangle ” is bisected into the SDW and the CDW regions by the border-line with U = S . The metastable SDW (CDW) phase exists in addition to the stable CDW (SDW) phase in a narrow region around the bisector. The border-lines for the metastable phases and the bisector between the two stable phases flow together into the T - vertex of the triangle, indicating the intriguing instability of one-dimensional metal against U and S .