Disentangling single- and biexciton dynamics with photoelectron-detected two-dimensional electronic spectroscopy

Description

Abstract (English)

Action-detected two-dimensional (2D) spectroscopy resolves the time-dependent nonlinear optical response of a quantum system by recording incoherently detected observables such as fluorescence, photoelectrons, or photocurrents which reflect the system’s excited-state population. Processes such as exciton–exciton annihilation alter this population and obscure, for instance, energy transfer processes. This limits the available information of action-detected 2D spectra compared to their coherently detected counterparts. Here we investigate time gating and kinetic-energy filtering in coherent optical 2D photoelectron spectroscopy to disentangle various processes. We implement a numerical simulation protocol that allows us to calculate 2D photoelectron spectra for various systems, demonstrating that time gating can extract the same information as coherently detected 2D spectroscopy, even when annihilation is present. Furthermore, we can directly infer annihilation dynamics. Kinetic-energy filtering additionally enables the isolation of specific excited-state dynamics. Our simulations demonstrate that time gating and kinetic-energy filtering are promising extensions for 2D photoelectron spectroscopy.