Rectifying fluctuations in an optical lattice

TL;DR

This paper demonstrates a Brownian motor using cold atoms in a symmetric optical lattice, where applying zero-mean ac forces rectifies fluctuations, illustrating a novel method of force and fluctuation rectification.

Contribution

It introduces an experimental realization of a Brownian motor in a dissipative optical lattice with symmetric potential by breaking time-symmetry with ac forces.

Findings

Identification of force rectification regime

Observation of fluctuation rectification regime

Demonstration of a Brownian motor in optical lattice

Abstract

We have realized a Brownian motor by using cold atoms in a dissipative optical lattice as a model system. In our experiment the optical potential is spatially symmetric and the time-symmetry of the system is broken by applying appropriate zero-mean ac forces. We identify a regime of rectification of forces and a regime of rectification of fluctuations, the latter corresponding to the realization of a Brownian motor.