Degeneracy of Ground State in Two-dimensional Electron-Lattice System

Abstract

We discuss the ground state of a two dimensional electron-lattice system described by a Su-Schrieffer-Heeger type Hamiltonian with a half-filled electronic band, for which it has been pointed out in the previous paper [J. Phys. Soc. Jpn. 69 (2000) 1769-1776] that the ground state distortion pattern is not unique in spite of a unique electronic energy spectrum and the same total energy. The necessary and sufficient conditions to be satisfied by the distortion patterns in the ground state are derived numerically. As a result the degrees of degeneracy in the ground state is estimated to be about $N^{N/4}$ for $N\gg 1$ with $N$ the linear dimension of the system.

2pages, 2figures

References in corpus (1)

• Peierls Distortion in Two-Dimensional Tight-Binding Model

Cited by in corpus (2)

• Multi-Modes Phonon Softening in Two-Dimensional Electron-Lattice System
• Berry's phase in the multimode Peierls states