On the Problem of the Existence of Davydov Solitons

Abstract

Davydov's soliton model, which introduces autolocalised excitations in a soft molecular chain, is applied also for explaining the energy transport process in the α‐helix protein being considered as a system consisting of three coupled molecular chains (spines). However, there is an inconsistency in the consideration of the single chain case compared to the case of coupled chains (α‐helix). Namely, in the Hamiltonian of the single molecular chain some relevant exciton‐photon terms are omitted which are, on the other hand, included in the Hamiltonian of the coupled chains. Our numerical analysis shows that the omitted term can have a very important influence on the soliton properties in Davydov's model. Copyright © 1995 WILEY‐VCH Verlag GmbH & Co. KGaA