"Electron photoemission in time-domain and the role of bosonic excitations"

Who: Y. Pavlyukh (Institut für Physik, Martin-Luther-Universität, Halle, Germany)

Place: Donostia International Physics Center

Date: Tuesday, 9 May 2017, 12:00

Electron photoemission in time-domain and the role of bosonic excitations

Y. Pavlyukh

Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, P.O. Box 3049, 67653 Kaiserslautern, Germany
Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle, Germany

Photoemission is a well-established instrument for physical studies with more than a hundred years history (photoelectric effect). Recent advances in ultrafast lasers and streaking techniques made it possible to trace the electron-photon, electron-plasmon and electron-phonon interactions accompanying this process on the attosecond timescale. In my talk I will address from theoretical point of view the following facets of such a dynamics: i) excitation of nonequilibrium plasmons in graphene by impinging electrons  and their spectroscopical observation [1]; ii) two-plasmon processes manifested in the spectral function of  3d homogeneous electron gas [2]; iii) time-delay of the electrons experiencing extrinsic and intrinsic energy losses [3] as observed in recent experiment on bulk Mg [4]; iv) transient build-up of plasmonic excitations in C60 and their decay by the emission of a secondary electron [5]. Description of these phenomena stipulated developments in many-body perturbation theory and nonequilibrium Green?s function formalism. A short overview of recent progress in these fields will be given.

References:

[1] Y. Pavlyukh, Padé resummation of many-body perturbation theories, Scientific Reports 7, 504 (2017)
[2] Y. Pavlyukh, A.-M. Uimonen, G. Stefanucci, and R. van Leeuwen Vertex Corrections for Positive-Definite Spectral Functions of Simple Metals, Phys. Rev. Lett.117, 206402 (2016)
[3] M. Schüler, J. Berakdar and Y. Pavlyukh, Time-dependent many-body treatment of electron-boson dynamics: Application to plasmon-accompanied photoemission, Phys. Rev. B 93, 054303 (2016)
[4] C. Lemell  et al. Real-time observation of collective excitations in photoemission, Phys. Rev. B 91, 241101(R) (2015)
[5] M. Schüler,Y. Pavlyukh, P. Bolognesi, L. Avaldi, and J. Berakdar, Electron pair escape from fullerene cage via collective modes, Scientific Reports 6, 24396 (2016)

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