Dynamic Jahn-Teller effect in fullerene C60 and related observable effects

Based on the Bogoliubov-de Gennes formalism, the linear multi-mode T1u ⊗ 8 hg static Jahn-Teller problem is analyzed for the charged C60−, C602−, the lowest triplet and singlet self-trapped exciton (STE) of C60. The dynamic Jahn-Teller effect due to quantum tunneling between the six degenerate D5d configurations is studied within a perturbation approach. The tunneling induced level splittings are determined to be 2T1u ⊕ 2T3u, 1Ag ⊕ 1Hg, 3T3g ⊕ 3T1g and 1T3g ⊕ 1T1g for C601-, C602-, triplet and singlet STEʹs of neutral C60, respectively. The observable consequences of the dynamic Jahn-Teller effect are considered. Some of the Jahn-Teller active (as well as Raman-active) modes are predicted to be observable as multi-phonon overtones in the infrared absorption. In the photo-induced multi-phonon resonant Raman scattering the tunnel splitting itself should show up in the Raman spectrum, and the depolarization ratio is sensitive to the exciting frequency.