Title: Phonon-mediated repulsion, sharp transitions and (quasi)self-trapping in the extended Peierls-Hubbard model 

Abstract: Particle-phonon coupling is generically expected to lead to a screening of the bare particleparticle interactions. If low-energy overscreening occurs, the resulting attractive interactions are responsible for conventional superconductivity as described by the Bardeen-CooperSchrieffer theory.  demonstrate that Peierls-type particle-phonon coupling not only leads to an enhanced repulsion between identical fermions/hard-core bosons, but also generates an additional effective interaction not of density-density type and thus not involved in screening. This interaction moves pairs of neighbor particles as a whole; this has unusual consequences such as a (quasi)self-trapping transition for a bound pair even when the individual particles are very mobile. These results open new directions in the study and understanding of the effects of particle-boson coupling, relevant for understanding behavior in Physics, e.g. in quantum materials; Chemistry, e.g. in optoelectronic processes; and Biology, e.g. in photosynthesis and DNA.