Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Exciton delocalization in the B850 light-harvesting complex : Comparison of different measures

Dahlbom, M. LU ; Pullerits, T. LU ; Mukamel, S. and Sundström, V. LU (2001) In Journal of Physical Chemistry B 105(23). p.5515-5524
Abstract

A much debated topic in recent studies of ultrafast exciton dynamics in molecular aggregates has been the precise definition of the exciton coherence domain in the B850 aggregate of photosynthetic purple bacteria. In this work we compare several measures of exciton delocalization and their variation with temperature, inhomogeneous broadening, and time. We find that the exciton wave packet prepared by a 40 fs pulse is initially delocalized over a substantial portion of the ring and contracts to a significantly smaller size on the time scale of a few hundreds of femtoseconds. Steady-state absorption and time-dependent pump-probe spectra of the B850 aggregate are simulated and compare well with previously reported experimental data. The... (More)

A much debated topic in recent studies of ultrafast exciton dynamics in molecular aggregates has been the precise definition of the exciton coherence domain in the B850 aggregate of photosynthetic purple bacteria. In this work we compare several measures of exciton delocalization and their variation with temperature, inhomogeneous broadening, and time. We find that the exciton wave packet prepared by a 40 fs pulse is initially delocalized over a substantial portion of the ring and contracts to a significantly smaller size on the time scale of a few hundreds of femtoseconds. Steady-state absorption and time-dependent pump-probe spectra of the B850 aggregate are simulated and compare well with previously reported experimental data. The calculated thermalized exciton wave packet size is in good agreement with previous experimental and theoretical estimates.

(Less)
Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry B
volume
105
issue
23
pages
10 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:0035859428
ISSN
1089-5647
DOI
10.1021/jp004496i
language
English
LU publication?
yes
id
3dfc206c-9142-4990-8932-154b80be88f0
date added to LUP
2025-10-28 16:30:48
date last changed
2025-10-30 15:41:48
@article{3dfc206c-9142-4990-8932-154b80be88f0,
  abstract     = {{<p>A much debated topic in recent studies of ultrafast exciton dynamics in molecular aggregates has been the precise definition of the exciton coherence domain in the B850 aggregate of photosynthetic purple bacteria. In this work we compare several measures of exciton delocalization and their variation with temperature, inhomogeneous broadening, and time. We find that the exciton wave packet prepared by a 40 fs pulse is initially delocalized over a substantial portion of the ring and contracts to a significantly smaller size on the time scale of a few hundreds of femtoseconds. Steady-state absorption and time-dependent pump-probe spectra of the B850 aggregate are simulated and compare well with previously reported experimental data. The calculated thermalized exciton wave packet size is in good agreement with previous experimental and theoretical estimates.</p>}},
  author       = {{Dahlbom, M. and Pullerits, T. and Mukamel, S. and Sundström, V.}},
  issn         = {{1089-5647}},
  language     = {{eng}},
  month        = {{06}},
  number       = {{23}},
  pages        = {{5515--5524}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Journal of Physical Chemistry B}},
  title        = {{Exciton delocalization in the B850 light-harvesting complex : Comparison of different measures}},
  url          = {{http://dx.doi.org/10.1021/jp004496i}},
  doi          = {{10.1021/jp004496i}},
  volume       = {{105}},
  year         = {{2001}},
}