Bipolaronic excitations of interacting electron(hole) gas in one-dimensional lattice model

By developing a diagonalization scheme we observe that the dynamics of interacting electrons or holes locally coupled to dispersionless phonon mode in one-dimensional lattice can be mapped into that of paired electron or hole states (bipolaronic states), which then gives a physically appealing picture of excitation modes of the interacting electron or hole gas. As a result, the bipolaronic model of the interacting electron or hole gas, obtained from Holstein–Hubbard Hamiltonian in one-dimensional lattice, exhibits normalization of the hopping terms and leads to a reduced effective mass of the bipolaron, which essentially gives support to the bipolaronic theory of high T_c superconductivity.