OPTICAL ABSORPTION INDUCED BY POLARON OF THE EXTENDED PEIERLS—HUBBARD SYSTEM IN THE MOTT PHASE

Abstract

One-dimensional strongly correlated electron system, which is accompanied by the interaction with the lattice, has attracted a great deal of interest. At half-filling, this system is a Mott insulator when the electron-lattice interaction is weak. We performed theoretical investigation of the stable ground state of the one-dimensional strongly correlated electron system in which one electron was doped from half-filling. We found that a polaron solution appears under conditions of comparatively strong electron-lattice interaction and the polaron delocalizes under conditions of weak electron-lattice interaction in the Mott phase. [R. Shirasaki, and K. Iwano, J. Phys. Soc. Jpn. 72 (2003) 2902.] Moreover, we investigated the optical conductivity in the appearance of the polaron in the Mott phase. We used the phase Hamiltonian which described the physical properties of the strongly correlated electron system. Our calculation shows that the optical absorption peak in the electron gap appears when the polaron is induced in the strongly correlated electron system.