Dynamic Jahn-Teller effect inC60: Self-trapped excitons and resonant Raman scattering

The dynamic Jahn-Teller problem is solved for the lowest triplet and singlet self-trapped excitons of ${\mathrm{C}}_{60}$. The resultant tunnel-split ${}_{}{}^3{}_{}{}^{}$ ${\mathit{T}}_{3\mathit{g}}$ ${\oplus }^3$ ${\mathit{T}}_{1\mathit{g}}$ states provide a good explanation for the available experimental data on the lowest triplet states. The observable consequences of this dynamical symmetry breaking in the photoinduced multiphonon resonant Raman scattering are explored in detail. The tunneling splitting itself should show up in the Raman spectrum, and the depolarization ratio (which can be normal or unusual, depending on exciting frequencies) is calculated explicitly.