Abstract

The description of exciton dynamics in molecular aggregates at finite temperatures has recently been shown to require the inclusion of dissipative contributions that have heretofore not been taken into account^1,2. The specific model considered so far has been the usual one of an exciton coupled to a bath of harmonic oscillators as described bv the Hamiltonian Here ${\text{a}}_{\text{h}}^{\text{+}}\left({\text{a}}_{\text{k}}\right)$ creates (destroys) an exciton of wave vector k and energy E_k, ${\text{b}}_{\text{qα}}^{+}\left({\text{b}}_{\text{q}\alpha }\right)$ creates (destroys) a phonon in branch α of wave vector q and energy ℏω_qα, and Γ_kqα is a coupling constant. The dynamics of the excitons is then desceibed by the exact equation of motion^1,2

© 1984 Optical Society of America