Application of a Su-Schrieffer-Heeger-like model to the intramolecular electron-phonon coupling inC60clusters

Abstract

We apply a Su-Schriefter-Heeger-like model to study intramolecular electron-phonon interaction for the undoped C60 molecule in which all the translational degrees of freedom for each site are considered. We find that the C60 molecule favors a dimerized ground state and the inclusion of the electron-phonon coupling modifies the phonon spectra such that all the frequencies of the phonon modes shift to red except the A"mode. We also present a semianalytical treatment for the ground-state properties supplemented to the numerical calculations.

Quantum fluctuations ofD5dpolarons onC60Wang1, Wang2, Liu3 et al. 1994Phys. Rev. B13020View full textAdd to dashboardCite

“…In fact, the binding energy of the D 5d polaron is rather small (of the order of 40 meV as seen from Ref. [12] and the present calculation), which is comparable with the zero point energy for some of the JT active h g modes. Therefore, it is important to consider the dynamic JT effects due to quantum fluctuations.…”

“…For this static JT problem, the dynamic matrix of the different symmetry configurations has to be positive-definite to guarantee the dynamical stability. It has been found that the D 3d symmetry is not dynamically stable within the BdeG formalism [12]. The self-trapped excitons in neutral and charged C 60 molecules have also been studied using this framework [13].…”

“…Meanwhile, within the Bogoliubov-de Gennes (BdeG) formalism, well-known in the literature of conducting polymers [10], a simple SSH-like Hamiltonian is adopted to deal with the multi-mode JT problem of the molecule and the D 5d symmetry structures of C 1− 60 and C 2− 60 have been obtained [11,12]. For this static JT problem, the dynamic matrix of the different symmetry configurations has to be positive-definite to guarantee the dynamical stability.…”

“…[12], we simulated dynamic evolutions for a SSH-like system to find the stationary ground state configurations of C 60 and C 1− 60 molecules. We found that the singlet stationary configuration of C 2− 60 also has D 5d symmetry.…”

Dynamical simulation of exciton dissociation in poly(para-phenylenevinylene) systems

“…Here we have used an extended version of the SSH-model which includes a three-dimensional (3D) description of the system based on internal coordinates (bond distances, bond angles [13,14] and dihedral angles). Since the changes in the geometrical variables following excitations or charge transport are small, these changes can be approximated with linear terms for p-electron hopping and classical harmonic terms for the potential energy of the s-system.…”