Internal vibrational structure of the three-dimensional large bipolaron

G. Iadonisi; V. Cataudella; G. De Filippis; V. Mukhomorov

doi:10.1007/s100510070079

EPJ

Internal vibrational structure of the three-dimensional large bipolaron

G. Iadonisi¹, V. Cataudella¹, G. De Filippis¹ and V. Mukhomorov²

¹ INFM and Department of Physical Science, Napoli, Italy
² Agrophysical Institute, St. Petersburg, 195220 Russia

Received: 23 March 2000
Revised: 24 July 2000
Published online: 15 November 2000

Abstract

The internal vibrational states of the large bipolaron are studied by using the strong coupling Bogolyubov-Tyablikov canonical transformation of coordinates, that takes into account the conservation of the total momentum of the system. The complete spectrum is explicitly calculated and the electronic and vibrational properties of the states are discussed. Moreover the comparison of the bipolaron ground state and the binding energies with the results of the path integral and the Lee-Low and Pines methods shows that the proposed approach provides a correct description of the large bipolaron even in the intermediate regime of the electron-phonon interaction.

PACS: 71.38.+i – Polarons and electron-phonon interactions / 78.30.-j – Infrared and Raman spectra