Ferromagnets for integrated atom optics

A ferromagnetic atom chip for trapping neutral atoms above a substrate is fabricated and characterized. The chip is capable of generating an anisotropic quadrupole trap with gradients in excess of 15 kG/cm at a distance of more than 100 μm from the surface. This is a promising route to the study of ultracold low dimensional systems, interferometry, and atom optics which require tight confinement, while alleviating the problems of fragmentation seen in wire-based chips.