https://doi.org/10.1140/epjb/e2005-00027-5
Lattice vibrational analysis of polyacene
1
Department of Physics, Fudan University, 200433 Shanghai, P.R. China
2
College of Physics, Hebei Normal
University, 050016 Shijiazhuang, P.R. China
Corresponding author: a cqw@fudan.edu.cn
Received:
27
October
2004
Published online:
11
February
2005
Within an extended Su-Schrieffer-Heeger model, we made a lattice
vibrational analysis of polyacene. In a singly-charged polyacene,
the ground state contains an interchain-coupled polaron of
quasi- symmetry, around which we found thirteen localized
modes in total. Among these localized modes, five (three
and two
) are infrared active, six (four Ag and two
) modes are Raman active, and the other two localized
modes are asymmetric, which are both infrared active and Raman
active. For the case a charged polaron is coupled with a neutral
soliton in a finite polyacene chain, the vibrational modes are
also calculated to display the coupling effect between
self-trapping excitations on phonons. It is found that the
localized phonons are determined mainly by the charged polaron,
but the number and frequencies of the localized modes are
influenced by the existence of the neutral soliton.
PACS: 63.22.+m – Phonons or vibrational states in low-dimensional structures and nanoscale materials / 63.20.Pw – Localized modes
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005