title: Vibronic energies and spectra of molecular dimers.
abstract: We consider three distinct methods of calculating the vibronic levels and absorption spectra of molecular dimers coupled by dipole-dipole interactions. The first method is direct diagonalization of the vibronic Hamiltonian in a basis of monomer eigenstates. The second method is to use creation and annihilation operators leading in harmonic approximation to the Jaynes-Cummings Hamiltonian. The adiabatic approximation to this problem provides insight into spectral behavior in the weak and strong coupling limits. The third method, which serves as a check on the accuracy of the previous methods, is a numerically exact solution of the time-dependent Schrodinger equation. Using these methods, dimer spectra are calculated for three separate dye molecules and show good agreement with measured spectra.
authors.affiliation: Fakultät für Mathematik und Physik, Universität Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Eisfeld
authors.forename: L
authors.initials: L
authors.lastname: Braun
authors.forename: W T
authors.initials: WT
authors.lastname: Strunz
authors.forename: J S
authors.initials: JS
authors.lastname: Briggs
authors.forename: J
authors.initials: J
authors.lastname: Beck
authors.forename: V
authors.initials: V
authors.lastname: Engel