Thermal Stability of the Davydov Soliton

Abstract

Although in the science of bioenergetics considerable progress has been made in the past 20 years, the storage and transport of energy in biological systems is not well understood. An answer to this problem was suggested in 1973 by Davydov, who proposed that quantum units of peptide vibrational energy (in particular the amide-I or C=O stretching vibration) might become ”self-localized” through interactions with lattice phonons^{1, 2}. Following his original suggestion many related studies have been published by Davydov and his colleagues³ and by others⁴ on this ”Davydov soliton”. The question of the thermal stability of the Davydov soliton at biological temperatures has also been studied by Davydov, in a quantum mechanical framework⁵ and by others in classical simulations^{6, 7}. Here results obtained following Davydov’s thermal treatment without any approximations are presented and the discrepancies between the latter and the classical simulations^{6, 7} are discussed. Finally, as a way to overcome the inconclusiveness of the latter approaches a search for exact dynamical solutions is proposed.