Transport induced by dichotomic temperature fluctuations

The transport process of a Brownian particle in a ratchet-like potential su bjected to two exchanging Gaussian white noises is studied. The change of t he temperatures is described by a stochastic dichotomic process. By making use of the perturbation method the probability current up to second order i n small correlation time tau is obtained, and time-averaged current is eval uated numerically for a whole region of the parameters. For asymptotically fast temperature cycles, the present model yields larger current in compari son with the periodical temperature cycles. Depending on the temperature of cold heat reservoir, the current changes sign as a function of tau.