Energy losses in a flashing ratchet with different potential well shapes

A flashing ratchet is considered, which involves periodic two-well potentials fluctuating via random shifts of one half-period. Such a Brownian motor exhibits the maximum efficiency tending to unity, provided one of the barriers blocks the reverse movement of a Brownian particle and the potential wells have the same curvatures and the half-period-shifted minima. Analytical expressions are derived for the energy losses arising from a discrepancy between potential well curvatures and a deviation of the inter-well distance from a half-period. The dependences of the energy losses on the parameters of the model are analyzed.