Simulating pump-probe experiments in electron-phonon coupled materials out to picosecond time scales: Creating a perfect conductor by driving a phonon to the unstable maximum of a double-well potential

The electron-phonon problem in nonequilibrium is solved using a semiclassical approach where the electrons are treated quantum mechanically and the phonons are treated classically via Ehrenfest forces. A classical Monte Carlo approach is then employed to describe the statistical averaging of the system. This approach allows us to examine pump-probe experiments for both electronic and photonics properties. In particular, we examine the case where a Fe to second pulse of the electrons impulses the phonons and drives them towards the unstable fixed point of a double-well potential. In this regime, which can be stabilized for a few ps, the system act like a perfect conductor, showing electronic current that has extremely long damping rates and Bloch oscillations that last for a ps or more. Our calculations show that this perfect conductor phase is metastable, but quite robust and should be able to be seen in experiment.