Band Splitting and Metal-Insulator Transition Driven by the Electron-Plasmon Interaction

Abstract

By reexamining the RPA electron self energy for a single band long range Coulomb interaction model of electrons, we raise the possibility that in a metal the electron-plasmon interaction, which is the dominant ingredient of the RPA consequence, may drive a band to split into three when the plasma frequency, ω _pl, is larger than the band width, W. The behavior of the band splitting is found to depend very sensitively on the unscreened exchange interaction between electrons, U, besides ω _pl, W, and the number of electrons per atom. We show that when U is much larger than W, such band splitting may induce a metal-insulator transition.