An adiabatic picture for electron transfer in mixed-valence systems

An adiabatic picture is proposed to analyze short-time electronic coherence and dephasing in mixed-valence systems, which cannot be described by the Redfield equation or the golden-rule rate theory. In this picture, electronic coherence arises from Rabi oscillations between two adiabatic surfaces and decays as a result of inhomogeneous distributions and thermal fluctuations of Rabi frequencies. The initial preparation and wavepacket dynamics modulate Rabi oscillations and thus influence electronic coherence. Comparisons between exact numerical results and the prediction from the proposed theory verify the accuracy of the adiabatic approximation in describing the short-time electronic dynamics.