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Here you can find upcoming events of the MPSD institute.

MPSD ARD Seminar

Shinji Saito - Supercooled water: Fluctuation, glass transition, and vibrational entropy

Water is the most common liquid. Its properties are not, however, common. Since the anomalies of water become pronounced at low temperatures, especially below its melting temperature, it has been proposed that the anomalous properties are attributed to the presence of two liquid states corresponding to the two amorphous ices. Experimental studies of supercooled water are however very difficult. This is due to the fact that bulk water is easily transferred to a crystalline phase in the “no man’s land”, which is a temperature range bounded by the crystallization of supercooled water at ~235K and by that of highly viscous liquid water at ~150K. Therefore, various theoretical and computational studies have been conducted for understanding the properties in the no man’s land. We have performed extensive molecular dynamics simulations from normal liquid to deeply supercooled states to reveal the structural and dynamical instabilities in the no man’s land. The spatiotemporal fluctuations, dynamic transition, glass transition, and vibrational contribution to Kauzmann temperature of supercooled water will be discussed. [more]

MPSD ARD Seminar

Lipeng Chen - Theory meets spectroscopy: ensemble and single-molecule spectroscopic studies of ultrafast energy transfer processes in light harvesting systems

To a large extent, our knowledge of the photoinduced dynamics of molecular systems at the atomic level is shaped by nonlinear femtosecond spectroscopy. Traditionally, nonlinear femtosecond spectroscopy is an ensemble spectroscopy, performed on ensembles of identical chromophores in the gas phase or in the liquid phase. Modern femtosecond spectroscopy comprises a set of various third-order or higher-order technique including, for example, fluorescence up conversion, transient absorption, and photon echo spectroscopy. Very recently, the portfolio of femtosecond techniques has been extended towards singlemolecule detection by the development of fluorescence-detected double-pump singlemolecule spectroscopy. With this technique, a temporal resolution of about ten femtoseconds has been achieved. The technique permits the real-time monitoring of not only electronic populations, but also of electronic and vibrational coherence for individual molecules. [more]