Stability and nature of polarons in a two-site two-electron model

Abstract

A two-site two-electron system is studied in the presence of an electron-phonon (e-ph) interaction and intersite hopping of the electrons to determine the stability of different polaronic states. Exact energies and eigenfunctions for the triplet and Anderson bipolaronic states are found. For the singlet bipolaronic state, the role of different phonon states in lowering the energy is discussed. The nature of polarons with the variation in e-ph coupling strength is studied.