Numerically Exact Nonadiabatic Dynamics of Electron-Phonon Lattice Models at Arbitrary Temperatures using Tensor Networks

A fundamental challenge in tailoring materials for charge transport applications is predicting how chemical structure determines a material’s transport properties. Non-equilibrium transport in polaron-forming materials has been studied extensively using the dispersive Holstein model which uses an effective spectral density to model the interactions of a fermionic lattice with a phonon bath. However, a first-principles understanding of the mechanisms that underlie transport phenomena such as diffusion or ballistic transport necessitates an exact treatment of both fermionic and bosonic dynamics. From a tensor network perspective, this has been particularly challenging at finite temperatures. In this talk, I will present our numerically exact tensor network method to obtain the dynamics of lattice models coupled to discrete phonon modes at arbitrary temperatures. I will illustrate the broad applicability of our approach by using it to study several polaron-forming lattice models, including the single-phonon mode Holstein model, at various temperatures. I will show how variations in temperature and electron-phonon coupling strength affect polaron formation and transport in different models.