Fabrication of an Atom Chip for Rydberg Atom-Metal Surface Interaction Studies

Abstract

This thesis outlines the fabrication of two atom chips for the study of interactions between ⁸⁷Rb Rydberg atoms and a Au surface. Atom chips yield tightly confined, cold samples of an atomic species by generating magnetic fields with high gradients using microfabricated current-carrying wires. These ground state atoms may in turn be excited to Rydberg states. The trapping wires of Chip 1 are fabricated using thermally evaporated Cr/Au and patterned using lift-off photolithography. Chip 2 uses a Ti/Pd/Au tri-layer, instead of Cr/Au, to minimize interdiffusion. The chip has a thermally evaporated Au surface layer for Rydberg atom-surface interactions, which is separated from the underlying trapping wires by a planarizing polyimide dielectric. The polyimide was patterned using reactive ion etching. Special attention was paid to the edge roughness and electrical properties of the trapping wires, the planarization of the polyimide, and the grain structure of the Au surface.