2023 |
|
2. | A. Adamkiewicz, M. Raths, M. Stettner, M. Theilen, L. Münster, S. Wenzel, M. Hutter, S. Soubatch, C. Kumpf, F. C.Bocquet, R. Wallauer, F. S. Tautz, U. Höfer Coherent and Incoherent Excitation Pathways in Time-Resolved Photoemission Orbital Tomography of CuPc/Cu(001)-2O Journal Article In: J.Phys. Chem. C, vol. 127, pp. 20411, 2023. Abstract | Links | BibTeX | Tags: Orbital Cinema @article{Adamkiewicz2023, Time-resolved photoemission orbital tomography (tr-POT) offers unique possibilities for tracing molecular electron dynamics. The recorded pump-induced changes of the angle-resolved photoemission intensities allow one to characterize unoccupied molecular states in momentum space and to deduce the incoherent temporal evolution of their population. Here, we show for the example of CuPc/Cu(001)-2O that the method also gives access to the coherent regime and that different excitation pathways can be disentangled by a careful analysis of the time-dependent change of the photoemission momentum pattern. In particular, we demonstrate by varying photon energy and polarization of the pump light how the incoherent temporal evolution of the LUMO distribution can be distinguished from coherent contributions of the projected HOMO. Moreover, we report the selective excitation of molecules with a specific orientation at normal incidence by aligning the electric field of the pump light along the molecular axis. |
1. | C. S. Kern, A. Windischbacher, P. Puschnig Photoemission orbital tomography for excitons in organic molecules Journal Article In: Phys. Rev. B, vol. 108, pp. 085132, 2023. Abstract | Links | BibTeX | Tags: Orbital Cinema @article{Kern2023, Driven by recent developments in time-resolved photoemission spectroscopy, we extend the successful method of photoemission orbital tomography (POT) to excitons. Our theory retains the intuitive orbital picture of POT, while respecting both the entangled character of the exciton wave function and the energy conservation in the photoemission process. Analyzing results from three organic molecules, we classify generic exciton structures and give a simple interpretation in terms of natural transition orbitals. We validate our findings by directly simulating pump-probe experiments with time-dependent density functional theory. |
2023 |
|
2. | Coherent and Incoherent Excitation Pathways in Time-Resolved Photoemission Orbital Tomography of CuPc/Cu(001)-2O Journal Article In: J.Phys. Chem. C, vol. 127, pp. 20411, 2023. |
1. | Photoemission orbital tomography for excitons in organic molecules Journal Article In: Phys. Rev. B, vol. 108, pp. 085132, 2023. |