Regensburg 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 63: Focus Session: Nanoscale Light-matter Interaction II
HL 63.3: Vortrag
Freitag, 21. März 2025, 12:30–12:45, H14
Accessing phase and group velocities of terahertz surface plasmon polaritons in graphene using near-field spacetime imaging — •Simon Anglhuber1, Martin Zizlsperger1, Eva A. A. Pogna2, Yaroslav A. Gerasimenko1, Anastasios D. Koulouklidis1, Imke Gronwald1, Svenja Nerreter1, Leonardo Viti3, Miriam S. Vitiello3, Rupert Huber1, and Markus A. Huber1 — 1Regensburg Center for Ultrafast Nanoscopy (RUN) and Department of Physics, University of Regensburg, 93040 Regensburg, Germany — 2Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche (CNR-IFN), Milano, I-20133, Italy — 3NEST, CNR - Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, Italy
The combination of light and matter properties in surface polaritons offers unprecedented opportunities for controlling energy flow and information processing at the nanoscale. Here, we present a novel THz near-field imaging approach to visualize polariton propagation directly in the time domain. Our method allows for the extraction of phase and group velocities, as well as damping. Thus, it reveals substantial insights into the polariton dispersion curve, even for strongly damped modes. Additionally, we show that our analysis can be expanded to two dimensions, directly visualizing polariton propagation in arbitrary directions, which is especially valuable for anisotropic materials. Finally, the method offers an intuitive approach to visualize non-equilibrium polariton propagation, e.g. upon photoexcitation. Thereby, we achieve subcycle control over polariton dynamics.
Keywords: terahertz; surface plasmon polaritons; near-field optical microscopy; graphene; ultrafast