<div dir="ltr">Hi all,<div><br></div><div>Prof. Shaul Mukamel of UC Irvine will be giving the last theoretical chemistry seminar of the semester this Wednesday from 4-6 PM in 4-163. His title and abstract are below. We hope to see you all there!</div><div><br></div><div><div class="gmail_default" style="font-size:12.8000001907349px;font-family:verdana,sans-serif"><b>Title:</b></div><span style="font-size:12.8000001907349px">Multidimensional Electronic And Vibrational Spectroscopy Of Molecules Using Attosecond X-Ray Pulses, Optical Pulses, And Quantum Light</span><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px"><div class="gmail_default" style="font-family:verdana,sans-serif"><b>Abstract:</b></div></div><div style="font-size:12.8000001907349px">The response of molecules to sequences of ultrafast optical pulses ranging from the infrared to the hard x-ray regimes provides novel windows into elementary molecular events and electronic and nuclear motions. Recent developments in this field involving the use of broadband x-ray pulses and entangled photons will be surveyed. New x-ray light sources are capable of triggering valence electron motions impulsively by a stimulated resonant Raman process via core excitations and monitoring them with high temporal and spatial resolution. Attosecond x-ray pulses can probe quantum coherence and correlations of valence electron and hole pairs, in an analogous manner to the way vibrational motions are investigated using femtosecond Raman techniques in the visible regime. By creating multiple core holes at controlled times and locations it becomes possible to study the dynamics and correlations of valence electrons as they respond to core hole perturbations. Applications will be presented to energy transfer in porphyrin aggregates, long-range biological electron transfer and multidimensional electron diffraction. A stimulated Raman detection of an X-ray probe may be used to monitor the phase and the dynamics of the nonequilibrium valence electronic state wavepacket created by e.g. photoexcitation, and photoionization. The passage through conical intersections can be directly monitored by observing electronic coherences. <br><br>Quantum spectroscopy utilizes the quantum nature of light to reveal matter properties not available with classical light. Quantum spectroscopy signals are recorded by varying parameters of the photon wavefunction rather than classical field envelopes. Entangled photons provide novel nonlinear spectroscopic probes of excitation energy transfer and charge separation processes in chromophore aggregates. The unusual spectral and temporal characteristics of entangled photon pairs combined with interferometric detection make it possible to manipulate and control multiple exciton states in photosynthetic reaction centers.<br><br>1. "Monitoring Long-range Electron Transfer in Proteins by Stimulated Broadband X-Ray Raman Spectroscopy", Yu Zhang, J.D. Biggs, Niri Govind, and Shaul <span class="">Mukamel</span>. JPC Lett, 5, 3656-3661 (2014) <br><br>2. "Stimulated Raman Spectroscopy with Entangled Light; Enhanced Resolution and Pathway Selection", K. Dorfman, F. Schlawin, and S. <span class="">Mukamel</span>. <a href="http://dx.doi.org/10.1021/jz501124a" target="_blank">dx.doi.org/10.1021/jz501124a</a> | J. Phys. Chem. Lett, 5, 2843-2849 (2014) <br><br>3. "Multidimensional Spectroscopy with Entangled Light; Loop vs. Ladder Delay Scanning Protocols", K.E. Dorfman and S. <span class="">Mukamel</span>. New J. Phys. 16, 033013 (2014) <br><br>4. "Catching Conical Intersections in the Act; Monitoring Transient Electronic Coherences by Attosecond Stimulated X-ray Raman Signals", Konstantin Dorfman, Kochise Bennett, Markus Kowalewski, and Shaul <span class="">Mukamel</span>. (In preparation, 2015)</div><div><br></div>-- <br><div class="gmail_signature">Michael Mavros<div>Department of Chemistry, Massachusetts Institute of Technology</div></div>
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