Ferruccio Renzoni

Brownian motors, or ratchets, are devices which "rectify" Brownian motion, i.e. they can generate a current of particles out of unbiased fluctuations.

We experimentally implemented a Brownian motor using cold atoms in an optical lattice. This is quite an unusual system for a Brownian motor as there is no a real thermal bath, and both the periodic potential for the atoms and the fluctuations are determined by laser fields.

With the help of such a system, we investigated experimentally the relationship between symmetry and transport in a rocking ratchet, both in the periodic and in the quasiperiodic case.