Effective interaction dynamics of Rydberg excitons

Abstract: Rydberg states of excitons in Cu$_2$O are known to interact strongly with other carriers in their surrounding such as other excitons, free charge carriers and static charged impurities. In cw-experiments, discriminating the individual processes is notoriously challenging. Here, we use a time-resolved two-color pump-probe setup and investigate the temporal evolution of Rydberg excitons with a resolution of 15 ns. The dynamic response of the Rydberg system to pump pulses with different energies is analyzed and the elementary processes that constitute the complex decay dynamics are compared among the different excitation scenarios. Our analysis reveals mainly four different timescales on which physical processes occur.