Nonequilibrium Bethe-Salpeter equation for transient photoabsorption spectroscopy
Nonequilibrium Bethe-Salpeter equation for transient photoabsorption spectroscopy
In this work, we propose an accurate first-principles approach to calculate the transient photoabsorption spectrum measured in pump-and-probe experiments. We formulate a condition of adiabaticity and thoroughly analyze the simplifications brought about by the fulfillment of this condition in the nonequilibrium Green's function (NEGF) framework. Starting from the Kadanoff-Baym equations, …