Experiments on a videotape atom chip: fragmentation and transport studies

Abstract

This paper reports on experiments with ultra-cold rubidium atoms confined in microscopic magnetic traps created using a piece of periodically-magnetized videotape mounted on an atom chip. The roughness of the confining potential is studied with atomic clouds at temperatures of a few microKelvin and at distances between 30 µm and 80 µm from the videotape-chip surface. The inhomogeneities in the magnetic field created by the magnetized videotape close to the central region of the chip are characterized in this way. In addition, we demonstrate a novel transport mechanism whereby we convey cold atoms confined in arrays of videotape magnetic micro-traps over distances as large as ∼ 1 cm parallel to the chip surface. This conveying mechanism enables us to survey the surface of the chip and observe potential-roughness effects across different regions.

Vortex based atom traps and atomic electrometry on a superconducting atom chip

“…In some circumstances, due to surface and edge roughness on the current-carrying wires, there is a distortion to the current flow which leads to corrugated trapping potential [24]. It has been shown by experiment that the atomic cloud (both thermal cloud [19,26,27,28] and BEC [19,24,29,30]) fragments in the vicinity of the current-carrying normal conducting wires [19,24,28,29,30] and Chapter 1. Introduction permanent magnets [26,27].…”