SOLID STATE & STRUCTURAL CHEMISTRY UNIT
INDIAN INSTITUTE OF SCIENCE
BANGALORE – 560 012
Dr. Vivek Tiwari
University of Michigan, USA
Spatially-resolved Two-dimensional Fluorescence-detected Electronic Spectroscopy
Date & Time : Tuesday 14th November, 2017 at 4:00 PM
Venue : SSCU Auditorium
Two-dimensional electronic spectroscopy (2D), which typically probes energetically and spatially averaged response from an ensemble of ~1010 units, has been widely employed to answer questions about the role of quantum coherence in photosynthetic function. Resonant non-adiabatic mixing of nuclear and electronic motions, first proposed by Tiwari, Peters and Jonas has increasingly been recognized as a possible mechanism of energy or charge transfer in photosynthesis. However, the proposed mechanism has led to a number of open questions regarding the true timescale of survival of electronic coherences. Similar questions regarding the spatial nature of energy transfer in a network of proteins inside a cell remain unexplored. Current 2D experiments do not provide the sensitivity and spatial resolution to answer such questions.
I will be discussing some of such open questions in natural and artificial systems, and the development of a fluorescence-detected spatially resolved 2D (2DFS) spectrometer as a step towards the ultimate goal of answering those questions. I will also present results from some recent 2DFS experiments on a toy dimer model of photosynthetic energy transfer, measurements of coherences from ~103 number of proteins in solution, and first measurements of spatially-resolved 2D spectra of micron-sized quantum dots and cell clusters.
ALL ARE CORDIALLY INVITED TO ATTEND