Relaxation Theory Applied to Scattering of Excitations and Optical Transitions in Crystals and Solids

Single Molecule Photon Counting Statistics for Quantum Mechanical Chromophore Dynamics

“…Physically, this can result from either a small coupling constant α or a large distance between the chromophore and TLS. As discussed above, in this case, results of the quantum model and stochastic model should be quite similar (at least for the line shapes [54]). In the left panes of fig.…”

“…Readers are referred there for a discussion, where we have employed notation identical to the present work. Determination of appropriate model parameters for the stochastic model, based upon the above quantum picture, is well established [54]. In the stochastic picture the TLS acts solely to modulate the transition frequency of the chromophore, causing hops between ω eg + ν and ω eg − ν.…”

“…The following description of coupled chromophore-TLS dynamics is quite terse. We refer readers to the review by Silbey [54] for more detail on the Redfield dynamics that we employ.…”

“…The coupling between TLS and chromophore enters as a different effective splitting between chromophore ground and excited states depending upon which minima the TLS resides in. Assuming this coupling is due to strain dipole interactions between chromophore and TLS we expect the interaction to scale as 1/r 3 in the distance between TLS and chromophore centers [54]. The basis of TLS "minima" states is not expected to be diagonal as tunneling may occur between minima.…”

“…The coupling constants g q are chosen to reflect strain field coupling between TLS and the phonon bath [54]; they scale with q as q 1/2 . The ij and kl suffixes on g q indicate that there are additional constants that need to be included -either J/ω e or J/ω g depending upon which specific terms the indices refer to.…”