In the quest for an optimal parametric regime of nonadiabatic switching ensuring low heat release in conjunction with high polarizability of mixed-valence molecular dimers

Abstract

The effects of electronic and vibronic interactions on the specific heat release occurring in the course of nonadiabatic switching of the electric field polarizing a one-electron mixed-valence dimer is analyzed within the framework of the Piepho–Krausz–Schatz vibronic model. The search for an optimal parametric regime from the point of view of minimizing heat release is carried out taking into account the requirement to maintain a strong nonlinear response of the dimer to the applied electric field. Calculations of the specific heat release and the response performed in the framework of the quantum mechanical vibronic approach show that although the heat release is minimal under a weak electric field acting on the dimer in combination with weak vibronic coupling and/or strong electron transfer, such a combination of the parameters is incompatible with the requirement of a strong nonlinear response. Unlike this, for molecules exhibiting strong vibronic interactions and/or weak transfer, a rather strong nonlinear response can be obtained even with a very weak electric field, which, in turn, ensures low heat release. Thus, we can conclude that an efficient strategy to improve characteristics of molecular quantum cellular automata devices or other molecular switchable devices based on mixed-valence dimers consists in usage of molecules subjected to the action of a weak polarizing field, which are characterized by strong vibronic coupling and/or weak transfer.