Controlling transport of underdamped particles in two-dimensional driven Bravais lattices

TL;DR

This paper demonstrates how the geometry of two-dimensional driven lattices can control the directed transport of underdamped particles, with potential experimental realizations using optical lattices and cold atoms.

Contribution

It reveals that lattice geometry alone can break spatial symmetry and control particle transport direction in driven underdamped systems, even when standard symmetry arguments fail.

Findings

Transport direction is determined by ballistic attractors in phase space.

Lattice geometry and drive parameters can be tuned to control transport.

Results are applicable to experimental setups with colloids or cold atoms.

Abstract

We demonstrate the directed transport of underdamped particles in two dimensional lattices of arbitrary geometry driven by an unbiased ac-driving force. The direction of transport can be controlled via the lattice geometry as well as the strength and orientation of the oscillating drive. The breaking of the spatial inversion symmetry, which is necessary for the emergence of directed transport, is achieved solely due to the structure and geometry of the lattice. The most important criterion determining the transport direction is shown to be the ballistic attractors underlying the phase space of our weakly dissipative non-linear dynamical system. This allows the prediction of transport direction even for setups like driven oblique lattices where the standard symmetry arguments of transport control fail. Our results can be experimentally realized using holographic optical lattice based setups with colloids or cold atoms.