arXiv subjects

P. Sjolund

Publications and source records attributed to P. Sjolund.

3 recordsLinked to original sources

arXiv2007

Influence of the lattice topography on a three-dimensional, controllable Brownian motor

We study the influence of the lattice topography and the coupling between motion in different directions, for a three-dimensional Brownian motor based on cold atoms in a double optical lattice. Due to controllable relative spatial phases between the lattices, our Brownian motor can induce drifts in arbitrary directions. Since the lattices couple the different directions, the relation between the phase shifts and the directionality of the induced drift is non trivial. Here is therefore this relation investigated experimentally by systematically varying the relative spatial phase in two dimensions, while monitoring the vertically induced drift and the temperature. A relative spatial phase range of 2pi x 2pi is covered. We show that a drift, controllable both in speed and direction, can be achieved, by varying the phase both parallel and perpendicular to the direction of the measured induced drift. The experimental results are qualitatively reproduced by numerical simulations of a simplified, classical model of the system.

physics.atom-ph↗

arXiv2007

Characterisation of a three-dimensional Brownian motor in optical lattices

We present here a detailed study of the behaviour of a three dimensional Brownian motor based on cold atoms in a double optical lattice [P. Sjolund et al., Phys. Rev. Lett. 96, 190602 (2006)]. This includes both experiments and numerical simulations of a Brownian particle. The potentials used are spatially and temporally symmetric, but combined spatiotemporal symmetry is broken by phase shifts and asymmetric transfer rates between potentials. The diffusion of atoms in the optical lattices is rectified and controlled both in direction and speed along three dimensions. We explore a large range of experimental parameters, where irradiances and detunings of the optical lattice lights are varied within the dissipative regime. Induced drift velocities in the order of one atomic recoil velocity have been achieved.

physics.atom-ph↗

arXiv2006

Generation of multiple power-balanced laser beams for quantum-state manipulation experiments with phase-stable double optical lattices

We present a method to obtain power-balanced laser beams for doing quantum-state manipulation experiments with phase-stable double optical lattices. Double optical lattices are constructed using four pairs of overlapped laser beams with different frequency. Our optical scheme provides a phase stability between the optical lattices of 5 mrad/s and laser beams with a very clean polarisation state resulting in a power imbalance in the individual laser beams of less than 1%.

physics.atom-ph↗