PHONON-MEDIATED ATTRACTION BETWEEN LARGE BIPOLARONS - CONDENSATION TO A LIQUID

Self-trapped carriers of large bipolarons are redistributed among sites of their molecular orbitals in response to atomic motions. This effect lowers the phonon frequencies. The dependence of the zero-point energy on the spatial distribution of large bipolarons produces a phonon-mediated attraction between them. This dynamic quantum-mechanical effect fosters the condensation of large bipolarons into a liquid at sufficiently low temperatures.