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Published on: October 9, 2012
Observation of an Excitonic Quantum Coherence in CdSe Nanocrystals
Shuo Dong1, Dhara Trivedi2, Sabyasachi Chakrabortty3
1Division of Chemistry and Biological Chemistry, and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371, Singapore.
Abstract:
Recent observations of excitonic coherences within photosynthetic complexes suggest that quantum coherences could enhance biological light harvesting efficiencies. Here, we employ optical pump-probe spectroscopy with few-femtosecond pulses to observe an excitonic quantum coherence in CdSe nanocrystals, a prototypical artificial light harvesting system. This coherence, which encodes the high-speed migration of charge over nanometer length scales, is also found to markedly alter the displacement amplitudes of phonons, signaling dynamics in the non-Born-Oppenheimer regime.
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