Coherent state description of lattice vibrations and high-temperature coherence effects

Usage of coherent states to describe the electromagnetic field paved the way for comprehensive understanding of coherence in quantum optics. Here we present a new description of lattice vibrations in terms of coherent states. When lattice vibrations are treated as coherent states, the deformation potential becomes a real field acting on electrons, making the electron-phonon interaction inherently non-perturbative. In the traditional approach, electron-phonon interactions are treated as the combination of uncorrelated successive first order events. On the contrary, in our approach, the lattice creates a disordered landscape where conduction electrons can quasi-elastically scatter, which preserves electron coherence beyond single collision events. This allows us to take the coherence of electrons into account. We find that preserved coherence effects cause electrons to Anderson localize even at high temperatures for a certain timescale. Furthermore, we compare our results with the literature by calculating electrical resistivity and observe a very good match for the regimes where the electron coherence effects do not play significant role. Coherent state picture of the lattice might have a potential to shed light on the universal resistivity of strange metals.