Fabrication of an atom chip for Rydberg atom-metal surface interaction studies

An atom chip has been fabricated for the study of interactions between ${}^{87}$Rb Rydberg atoms and a Au surface. The chip tightly confines cold atoms by generating high magnetic field gradients using microfabricated current-carrying wires. These trapped atoms may be excited to Rydberg states at well-defined atom-surface distances. For the purpose of Rydberg atom-surface interaction studies, the chip has a thermally evaporated Au surface layer, separated from the underlying trapping wires by a planarizing polyimide dielectric. Special attention was paid to the edge roughness of the trapping wires, the planarization of the polyimide, and the grain structure of the Au surface.