Fully Anharmonic, Non-Perturbative Theory of Vibronically Renormalized Electronic Band Structures

Understand

We develop a first-principles approach for the treatment of vibronic interactions in solids that overcomes the main limitations of state-of-the-art electron-phonon coupling formalisms.

• In particular, anharmonic effects in the nuclear dynamics are accounted to all orders via ab initio molecular dynamics simulations.
• This non-perturbative, self-consistent approach evaluates the response of the wave functions along the computed anharmonic trajectory; thus it fully considers the coupling between nuclear and electronic degrees of freedom.
• We validate and demonstrate the merits of the concept by calculating temperature-dependent, momentum-resolved spectral functions for silicon and the cubic perovskite SrTiO3, a strongly anharmonic material featuring soft modes.