2 REASONS WHY THE DAVYDOV SOLITON MAY BE THERMALLY STABLE AFTER ALL

Davydov has proposed a mechanism for energy transfer in proteins, according to which the energy liberated in an enzymatic reaction can be stored and transported in the form of a soliton. In recent years a debate has been going on concerning the thermal stability of the Davydov soliton. Here it is shown, first, that the two-quantum state is visibly more stable than the one-quantum state, and, second, that the usual Langevin dynamics, whereby the thermal lifetime of the Davydov soliton is estimated, must be viewed as underestimating, possibly very strongly, the soliton lifetime. © 1994 The American Physical Society.