Strong-coupling effects probed by electron beams
Strong couplings between quantum particles lead to novel quasi-particles with exotic properties. Particularly interactions between photons and room temperature excitons in van der Waals materials, form exciton-polaritons under certain circumstances, with applications in Bose-Einstein condensation or optoelectronics. Here, we demonstrate that exciton-polaritons can exist in Bi2Se3 thin films, in the form of surface and edge hyperbolic exciton polaritons. We also show the existence of exciton-polaritons in WSe2 thin films and demonstrate, using cathodoluminescence spectroscopy, that the coupling strength between photons and excitons could be further controlled using Bloch Plasmons allowing to tuning the density of the photonic states into an unprecedented extreme level.
Christian-Albrechts-Univ. zu Kiel (Germany)
Nahid Talebi is an associate professor and a director of the Institute for Experimental and Applied Physics in Kiel University, Germany, holding the chair for Nanooptics. Her work focuses on electron-photon interactions, ultrafast nanooptics, and electrodynamics. She graduated from Tehran University with a PhD in Electrical Engineering in 2011, defended with distinction. During her studies, she visited the Max Planck Institute in Stuttgart for the duration of 7 months with a Scholarship from the Max Planck Society. In 2012, she joined the Stuttgart Center for Electron Microscopy as an Alexander von Humboldt Research Fellow. In 2015, she became a group leader at the Max Planck Institute for Solid State Research and in 2018, she received an ERC Starting Grant from the European Research Council.