题目：Ultrafast Multidimensional Spectroscopy for Molecular Polaritons
Quantum states of the light, e.g., single photons, entanglement and squeezing, opens up a new avenue for spectroscopy by utilizing the parameters of quantum optical fields as novel control knobs and through the variation of photon statistics. With the advance of cavity quantum electrodynamics and light source technology, imaging and controlling the electron and vibrational motions of molecules can be achieved, towards unprecedented resolution and precision, not accessible by the classical light pulses. Two key issues emerge in nanoscale: quantum states of photons and strong matter-light interaction. The underlying physics is still an open issue for molecules and spectroscopy. In this talk, I will present our recent work on ultrafast multidimensional spectroscopic probes for ultrafast dynamics of molecular polaritons. Several spectroscopic signals will be covered: multidimensional coherent probe, photon-coincidence counting, and Raman spectra with quantum fields. Microscopic models for molecular polaritons using reduced density matrix and Heisenberg-Langevin approach will be incorporated for a unified understanding of the spectroscopic signals.
Prof. Zhedong Zhang is now an Assistant Professor in Department of Physics at City University of Hong Kong. He obtained his Ph.D. in physics from Stony Brook University in 2016. Since then, he has been working with Shaul Mukamel, Girish Agarwal and Marlan Scully (NAS, FRS & AAAS), as a postdoctoral scholar. He received the Robert A. Welch Postdoctoral Fellowship in 2020. Prof. Zhang is a member of American Physical Society.
Prof. Zhang’s research interest is the theoretical quantum physics, focusing on two fields: (1) Nonlinear optical spectroscopy with quantum light for time-, frequency- and spatial-resolved molecular relaxation; (2) Quantum thermodynamics for nanomaterials which aims at the mesoscopic thermodynamics emerging from quantum mechanics. He has about 30 professional publications, on high-profile journals including Phys. Rev. Lett., Optica, Light: Sci. & Appl., J. Phys. Chem. Lett., Phys. Rev. A and Phys. Rev. B.