Algorithmic complexity of thermal ratchet motion

Thermal ratchets are Brownian models where time-correlated fluctuations com ing from a nonequilibrium bath interacting with a spatial asymmetry are suf ficient conditions to give rise to transport. The nonequilibrium bath acts as a source of negentropy (physical information). Tn order to quantitate th e transfer of information that occurs in thermal ratchet motion, the Kolmog orov information entropy or algorithmic complexity is investigated. The com plexity is measured in terms of the average number of bits per time unit ne cessary to specify the sequence generated by the system. (C) 1998 Elsevier Science B.V.