Ruoyi Yin L&S Sciences
Exploring Core-Exciton States and Transitions in Four-Wave Mixing (FWM) Experiment
Probing core-exciton dynamics and its coupling behavior with carriers and optical fields by utilizing nonlinear wave-mixing spectroscopy can uncover the fundamental electronic and optical properties for materials and provide insights for electronic device manipulation. The nonlinear attosecond Four-Wave-Mixing (FWM) spectroscopy, using one extreme ultraviolet (XUV) light pulse followed by two optical pulses with controllable delays, has recently been used to evaluate gas-phase and condensed-phase materials. My project aims to use this technique to explore the core-exciton absorption in tungsten disulfide, a two-dimensional semiconductor and transition metal dichalcogenide. Photon energy range of the XUV pulse is suitable for exploring core-level spectra, while the optical pulse probes the core-exciton state evolution and decoherence through decay. During this project, the absorption spectra, population decay time, and core-exciton state evolution can be displayed experimentally, while the corresponding core-exciton wave function in real space and oscillator strengths between the bright and dark excitonic states can be explored through computational calculation.