Pump-probe photoemission simulated in real time: Revealing many-particle signatures

We simulate the photoemission from an electronically excited system by computing the escape of electron density in real space using time-dependent density functional theory in real time. We show that for a one-electron system, the angular resolved photoemission after an initial excitation can be interpreted as the mapping of a previously unoccupied orbital. For the molecule perylene-3,4,9,10-tetracarboxylic dianhydride, the angular resolved photoemission (ARPES) calculated after a preceding pump pulse reveals signatures of the many-particle character of the first electronic excitation: The photoemission results from more than one time-dependent orbital, and comparing the ARPES pattern to a particle-hole analysis of the first electronic excitation confirms that the excitation does not just correspond to one electron having been moved into a previously empty orbital, but is a superposition of several single-particle excitations.

Automated summary

We simulate photoemission from an electronically excited system by computing electron density escape in real space in real time. For a one-electron system, angular resolved photoemission can be interpreted as the mapping of a previously unoccupied orbital. In the molecule perylene-3,4,9,10-tetracarboxylic dianhydride, angular resolved photoemission reveals signatures of the many-particle character of the first electronic excitation.