Ultrafast energy relaxation in single light-harvesting complexes
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10333730" target="_blank" >RIV/00216208:11320/16:10333730 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1073/pnas.1522265113" target="_blank" >http://dx.doi.org/10.1073/pnas.1522265113</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1073/pnas.1522265113" target="_blank" >10.1073/pnas.1522265113</a>
Alternative languages
Result language
angličtina
Original language name
Ultrafast energy relaxation in single light-harvesting complexes
Original language description
Energy relaxation in light-harvesting complexes has been extensively studied by various ultrafast spectroscopic techniques, the fastest processes being in the sub-100-fs range. At the same time, much slower dynamics have been observed in individual complexes by single-molecule fluorescence spectroscopy (SMS). In this work, we use a pump-probe-type SMS technique to observe the ultrafast en- ergy relaxation in single light-harvesting complexes LH2 of purple bacteria. After excitation at 800 nm, the measured relaxation time distribution of multiple complexes has a peak at 95 fs and is asym- metric, with a tail at slower relaxation times. When tuning the exci- tation wavelength, the distribution changes in both its shape and position. The observed behavior agrees with what is to be expected from the LH2 excited states structure. As we show by a Redfield theory calculation of the relaxation times, the distribution shape cor- responds to the expected effect of Gaussian disorder of the pigment transition energies. By repeatedly measuring few individual com- plexes for minutes, we find that complexes sample the relaxation time distribution on a timescale of seconds. Furthermore, by compar- ing the distribution from a single long-lived complex with the whole ensemble, we demonstrate that, regarding the relaxation times, the ensemble can be considered ergodic. Our findings thus agree with the commonly used notion of an ensemble of identical LH2 complexes experiencing slow random fluctuations.
Czech name
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Czech description
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Classification
Type
J<sub>x</sub> - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
CF - Physical chemistry and theoretical chemistry
OECD FORD branch
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Result continuities
Project
<a href="/en/project/GA14-25752S" target="_blank" >GA14-25752S: Microscopic environmental determinants and self-regulation of photosynthetic energy transfer</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2016
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Proceedings of the National Academy of Sciences of the United States of America
ISSN
0027-8424
e-ISSN
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Volume of the periodical
2016
Issue of the periodical within the volume
113
Country of publishing house
US - UNITED STATES
Number of pages
6
Pages from-to
2934-2939
UT code for WoS article
000372014200051
EID of the result in the Scopus database
2-s2.0-84962554260