Exciton-polaritons emerging from the interaction of photons and excitons in the strong coupling regime are intriguing quasiparticles for the potential exchange of energy during light-matter interaction processes such as light harvesting. The coupling causes an energy anti-crossing in the photon dispersion centered around the exciton resonance, i.e., a Rabi splitting between a lower and upper energetic branch. The size of this splitting correlates with the coupling strength between the exciton and the photonic modes. In this work, we investigate this coupling between excitons and photonic waveguide modes excited simultaneously in thin-film flakes of the transition-metal dichalcogenide WSe$_2$. Using a Photoemission electron microscope, we are able to extract the dispersion of the transversal electric and magnetic modes propagating through these flakes as well as extract the energy splitting. Ultimately, our findings provide a basis for the investigation of the propagation of exciton-polaritons in the time-domain via time-resolved photoemission.
Quasiparticle phono-conversion: filming carriers coalescing into excitons
Università di Roma Tor Vergata（罗马托尔维加塔大学）；INFN, Sezione di Roma Tor Vergata（意大利国家核物理研究所罗马托尔维加塔分部）；Okinawa Institute of Science and Technology Graduate University（冲绳科学技术大学院大学）；University of Gdansk（格但斯克大学）；Brookhaven National Laboratory（布鲁克海文国家实验室）
Quasi-steady electron-excitonic complexes coupling in a two-dimensional semiconductor
Institute for Advanced Studies, Wuhan University（武汉大学高等研究院）；Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所和凝聚态物理北京国家实验室）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；Songshan Lake Materials Laboratory（松山湖材料实验室）；Wuhan Institute of Quantum Technology（武汉量子技术研究院）
