The effect of self-affine fractal roughness of wires on atom chips

Atom chips use current flowing in lithographically patterned wires to produce microscopic magnetic traps for atoms. The density distribution of a trapped cold atom cloud reveals disorder in the trapping potential, which results from meandering current flow in the wire. Roughness in the edges of the wire is usually the main cause of this behaviour. Here, we point out that the edges of microfabricated wires normally exhibit self-affine roughness. We investigate the consequences of this for disorder in atom traps. In particular, we consider how closely the trap can approach the wire when there is a maximum allowable strength of the disorder. We comment on the role of roughness in future atom--surface interaction experiments.Comment: 7 pages, 7 figure

Design optimization of an electrostatic MEMS actuator with low spring constant for an "Atom Chip"

peer reviewe

Design, fabrication and testing of tunable microcavities for atom chips

peer reviewe

Performance of an electrostatic actuator for tunable optical microcavities

peer reviewe

A three-dimensional electrostatic actuator with a locking mechanism for microcavities on atom chips

A micromachined three-dimensional electrostatic actuator that is optimized for aligning and tuning optical microcavities on atom chips is presented. The design of the 3D actuator is outlined in detail, and its characteristics are verified by analytical calculations and finite element modelling. Furthermore, the fabrication process of the actuation device is described and preliminary fabrication results are shown. The actuation in the chip plane which is used for mirror positioning has a working envelope of 17.5 µm. The design incorporates a unique locking mechanism which allows the out-of-plane actuation that is used for cavity tuning to be carried out once the in-plane actuation is completed. A maximum translation of 7 µm can be achieved in the out-of-plane direction

Integration of a tuneable optical micro-cavity for single atom detection on an atom chip

peer reviewe

A three-dimensional electrostatic actuator with a locking mechanism for a new generation of atom chips

peer reviewe