报告题目：Nonlinear Spectroscopy and Imaging of Elementary Molecular Events and Chirality Using X-ray Pulses
报告人：Prof. Shaul Mukamel
主持人：Prof. Konstantin Dorfman
时间：2018-12-27 10:00
地点：理科大楼A814
报告人简介：
Shaul Mukamel is a Distinguished Professor of Chemistry and of Physics and Astronomy at UC Irvine and a member of the National Academy of Science. He received his Ph.D. degree from Tel Aviv University and served on the faculty at Rice University, the Weizmann Institute, and the University of Rochester. His research focuses on the design of ultrafast multidimensional coherent optical spectroscopies in molecules which span from the infrared to the X-ray spectral regimes and are used for probing and controlling electronic and vibrational molecular dynamics in the condensed phase. His theoretical and computational work shows how to employ these techniques to study energy and electron transfer in photosynthetic complexes, excitons in semiconductor nanostructures, and the secondary structure of proteins. His recent effort includes attosecond X-ray spectroscopy, utilizing the quantum nature of optical fields and photon entanglement to achieve temporal and spectral resolutions not possible with classical light, and nonlinear spectroscopy of nonadiabatic dynamics at concial intersections of molecules dressed by photons in microcavities. He is the author of over 900 publications and the textbook Principles of Nonlinear Optical Spectroscopy (1995), which paved the way for the field of multidimensional spectroscopy. His recent awards include the Ahmed Zewail ACS Award in Ultrafast Science and Technology, the Coblentz Society ABB Sponsored Bomem-Michelson Award, the William F. Meggers Award of OSA, and senior Humboldt and FRIAS fellowships.
报告内容简介：
Newly developed free electron laser and high harmonic generation x-ray sources offer unique probes of molecules with atomic-scale and attosecond time resolutions. A phase-cycling approach for simulating nonlinear x-ray signals is presented. Sum frequency generation diffraction signals are predicted for donor/acceptor conjugated systems and formyl fluoride. These provide images of transition charge densities, which reveal the dynamics of electronic excitations and coherences. A novel technique for imaging spontaneous electron density fluctuations by multiple single-photon diffraction events detected in coincidence is discussed. It is demonstrated how X-ray pulses can offer a unique local probe of chirality and its variation within molecules. Coherent control techniques, frequency combs and stimulated Raman processes will be used to study electron and nuclear dynamics. A wavelet analysis is presented for singling out the contributions of few valence electrons out of the strong background of core electrons in time resolved diffraction. This is essential for the monitoring of bond forming and breaking. The technique is demonstrated for the photocylclic ring opening diffraction signals in cyclohexaliene.
REFERENCES
[1] Markus Kowalewski, Benjamin Fingerhut, Konstantin Dorfman, Kochise Bennett and Shaul Mukamel. “Simulating Coherent Multidimensional Spectroscopy of Nonadiabatic Molecular Processes; from the Infrared to the X-ray Regime”, Chem. Rev., 2017, 117 (19), pp 12165–12226.
[2] Vladimir Osipov, Markus Kowalewski, and Shaul Mukamel. “Multiscale wavelet decomposition of time resolved x-ray diffraction signals in cyclohexadiene”, PNAS, 115 (41) 10269-10274 (2018)
[3] Jérémy R. Rouxel, Markus Kowalewski, Kochise Bennett, Shaul Mukamel. “X-Ray sum frequency generation; direct imaging of ultrafast electron dynamics”, Phys. Rev. Lett. 120, 243902 (2018) DOI: 10.1103/PhysRevLett.120.243902
[4] Jérémy R. Rouxel, Yu Zhang, and Shaul Mukamel. “X-ray Raman optical activity of chiral molecules”, Chemical Science (2018) DOI: 10.1039/c8sc04120b
[5] Lyuzhou Ye, Jérémy R. Rouxel, Daeheum Cho, and Shaul Mukamel. “Imaging electron-density flucutations by multidimensional X-ray photon-coincidence diffraction”, PNAS (In Press, 2018)