"Stroboscopic Tests for Thermalization of Electrons in Pump-Probe Experiments"

O. P. Matveev: M. Shvaika, T. P. Devereaux, and J. K. Freericks; Physical Review Letters, 06/19/19.

Additional Authors: M. Shvaika, T. P. Devereaux, and J. K. Freericks

Abstract:

One of the goals of pump-probe spectroscopies is to determine how electrons relax after they have been drivenout of equilibrium. It is challenging to determine how close electronsare to athermal state solely by fitting their distribution to a Fermi-Dirac distribution. Instead, we propose that one compare the effective temperatures of both fermions and collective bosonic modes (derived from the fermions) to determine the distance from a thermal state. Measurements of effective fermionic and bosonic temperatures can be achieved directly via photoemission and nonresonant Raman scattering. Their difference quantifies the distance from thermal equilibrium.