Polariton-Mediated Ultrafast Nonlinear Energy Transfer in a van der Waals Superlattice
Summary of Achievement
The research conducted by Prof. Yu-Jung Lu and her collaborators was recently published in ACS Nano. RCAS researcher Prof. Lu, along with an international research team led by Prof. Deep Jariwala from UPenn, introduced an innovative material platform featuring large-area monolayer WS₂/Al₂O₃ superlattices (with a square dimension exceeding 0.5 cm). These superlattices are coupled to a waveguide mode designed to host exciton-polaritons operating at room temperature. Time-resolved transient absorption spectra show picosecond nonlinear energy transfer phenomena between upper and lower polariton states, clarifying the dynamic behavior within this quantum realm. In addition, the research team observed population inversion behavior between the two polariton states that facilitate potential avenues for creating polariton-based ultrafast modulators and switches. This research not only advances our fundamental understanding of polariton dynamics but also promotes the development of innovative technologies that harness these fascinating quantum phenomena.
