Hannover 2010 – wissenschaftliches Programm
SYQS 1.2: Hauptvortrag
Donnerstag, 11. März 2010, 11:00–11:30, E 415
Quantum Control Spectroscopy: Understanding photobiology with coherently controlled matter waves — •Tiago Buckup1,2, Jürgen Hauer3, Judith Voll4, Regina Vivie-Riedle4, and Marcus Motzkus1,2 — 1Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität, D-69120 Heidelberg, Germany. — 2Physikalische Chemie, Philipps-Universität, D-35043 Marburg, Germany. — 3Department of Physical Chemistry, University of Vienna, A-1090 Vienna, Austria. — 4Department Chemie, Ludwig-Maximilians-Universität, D-81377 München, Germany.
The combination of coherent control methods with time-resolved spectroscopy, namely Quantum Control Spectroscopy (QCS), is a compelling approach to disentangle ultrafast dynamics . In particular, QCS can be very rewarding to investigate complex systems, such as light-harvesting complexes, where very often the traditional pump-probe spectroscopy fails. We report an experiment using phase-modulated degenerate four-wave mixing and provide a general mechanism for phase-only control of an open quantum system with an ultrashort excited state lifetime. We show by the use of coherent control that a low-frequency bending motion (178 cm−1 in β-carotene) is the driving force behind the photophysically relevant step in carotenoids, a central constituent of many light harvesting complexes. We can now rationalize pulse shapes found in a whole class of quantum control experiments, ranging from simple dye molecules to embed-protein chromophores like all-trans-retinal in bacteriorhodopsin.
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