  The spreading of a cloud of independent Brownian particles typically proceeds
more effectively at higher temperatures, as it derives from the commonly known
Sutherland-Einstein relation for systems in thermal equilibrium. Here, we
report on a non-equilibrium situation in which the diffusion of a periodically
driven Brownian particle moving in a periodic potential decreases with
increasing temperature within a finite temperature window. We identify as the
cause for this non-intuitive behaviour a dominant deterministic mechanism
consisting of a few unstable periodic orbits embedded into a chaotic attractor
together with thermal noise-induced dynamical changes upon varying temperature.
The presented analysis is based on extensive numerical simulations of the
corresponding Langevin equation describing the studied setup as well as on a
simplified stochastic model formulated in terms of a three-state Markovian
process. Because chaos exists in many natural as well as in artificial systems
representing abundant areas of contemporary knowledge, the described mechanism
may potentially be discovered in plentiful different contexts.
