Lifetime of the Davydov soliton

Quantum and thermal effects on the lifetime of the Davydov soliton are studied. Results of a quantum-mechanical perturbation treatment of the lifetime are presented for a wide range of parameter values. We derive a simple condition on the parameter values that must be satisfied for the soliton to be a viable mechanism for localized energy transport in the Davydov model for the {α}-helix region of protein. Our conclusion is that the Davydov soliton as originally proposed is not a likely candidate for this mechanism, but that a single soliton with a very large excitation number could provide the mechanism.