Yi-Fan Chiu, an M.S. student from National Taiwan Normal University, Taiwan, advised by Prof. Ting-Hua Lu, was visiting Charles University from March 1 to March 31 as part of an ongoing international research collaboration. During his stay, he was working under the supervision of Jana Vejpravová at the Department of Condensed Matter Physics, Faculty of Mathematics and Physics, within the Physics of Nanostructures Group.
His research focuses on light–matter interactions in monolayer MoS2, with particular emphasis on structured light carrying orbital angular momentum (OAM). The work explores how OAM-dependent excitation influences excitonic processes, Raman scattering, and polarization-resolved optical responses in two-dimensional materials.
During his visit, Yi-Fan Chiu performed low-temperature optical measurements using a Physical Property Measurement System (PPMS) integrated with a newly developed twisted light excitation setup. The experimental measurements were carried out in collaboration with and under the guidance of Rahul Kesarwani, who developed and implemented the twisted light spectroscopy setup. Experiments conducted at cryogenic temperatures (~4 K) enable detailed investigation of localized excitons and provide deeper insight into exciton–phonon coupling and angular momentum transfer mechanisms.
This visit represents one of the first collaborative studies utilizing the newly developed twisted light platform, marking an important step toward expanding global research collaborations in the field of structured light and 2D materials. The work also contributes to advancing potential applications in valleytronics and quantum photonics.
