Electronic Double-Quantum Coherences and Their Impact on Ultrafast Spectroscopy: The Example of beta-Carotene

Author(s)
Niklas Christensson, Franz Milota, Alexandra Nemeth, Igor Pugliesi, Eberhard Riedle, Jaroslaw Sperling, Tönu Pullerits, Harald Kauffmann, Jürgen Hauer
Abstract

The energy level structure and dynamics of biomolecules are important for understanding their photoinduced function. In particular, the role of carotenoids in light-harvesting is heavily studied, yet not fully understood. The conventional approach to investigate these processes involves analysis of the third-order optical polarization in one spectral dimension. Here, we record two-dimensional correlation spectra for different time-orderings to characterize all components of the transient molecular polarization and the optical signal. Single- and double-quantum two-dimensional experiments provide insight into the energy level structure as well as the ultrafast dynamics of solvated beta-carotene. By analysis of the lineshapes, we obtain the transition energy and characterize the potential energy, surfaces of the involved states. We obtain direct experimental proof for an excited state absorption transition in the visible (S-2 -> S-n2). The signatures of this transition in pump-probe transients are shown to lead to strongly damped oscillations with characteristic pump and probe frequency dependence.

Organisation(s)
Department of Physical Chemistry, Electronic Properties of Materials
External organisation(s)
Lund University, Ludwig-Maximilians-Universität München, Newport Spectra-Physics Gmbh
Journal
The Journal of Physical Chemistry Letters
Volume
23
Pages
3366-3370
No. of pages
5
DOI
https://doi.org/10.1021/jz101409r
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
104017 Physical chemistry, 1030 Physics, Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/e9b79164-ce05-4207-aa9b-280b2510df44