Multiphonon processes of the inelastic electron transfer in olfaction.

Inelastic electron transfer, regarded as one of the potential mechanisms to explain odorant recognition in atomic-scale processes, is still a matter of intense debate. Here, we study multiphonon processes of electron transfer using the Markvart model and calculate their lifetimes with the values of key parameters widely adopted in olfactory systems. We find that these multiphonon processes are as quick as the single phonon process, which suggests that contributions from different phonon modes of an odorant molecule should be included for electron transfer in olfaction. Meanwhile, the temperature dependence of electron transfer could be analyzed effectively based on the reorganization energy which is expanded into the linewidth of multiphonon processes. Our theoretical results not only enrich the knowledge of the mechanism of olfaction recognition, but also provide insights into quantum processes in biological systems.