Atom chips are microfabricated devices to trap and manipulate ultracold neutral atoms. They are used in some of the fastest ultracold atom sources, and provide strong, modulable and dynamic potentials for cold atom manipulation with unrivalled precision. Most atom chips contain current-carrying wires to generate magnetic potentials, which can be combined with other on-chip structures depending on the applications. Coplanar microwave guides excite atomic clock transitions or generate state-dependent potentials, and optical structures for trapping and readout have also been integrated. Their miniaturization and fast, low-power operation makes atom chips ideal for portable cold atom applications, such as atom interferometry, while their microscopically controlled “designer potentials” have enabled elegant original research in quantum metrology, one-dimensional quantum physics, atom-surface interactions, and many other fields. Our team has been at the forefront of atom chips research for many years.
As part of the first Quantus collaboration, we have provided the atom chips for the first BEC in microgravity, produced in a spectacular free-fall experiment in the 146m drop tower in Bremen, Germany. The project culminated with the demonstration a Mach-Zehnder atom interferometer operated with a Bose-Einstein condensate, using once again an atom chip produced in the ENS cleanroom.
Early atom chip experiments still needed a bulky vacuum apparatus with dedicated vacuum feedthroughs for each of the chip’s wires. Dana Z. Anderson and Jakob Reichel then pushed miniaturization and integration one step further by making the atom chip one of the walls of the vacuum cell. This powerful and radically simplified approach led to the foundation of ColdQuanta Inc. in 2007. ColdQuanta became the first company to offer commercial atom chip products.
To combine the versatility and integration of atom chips with the power of cavity QED, we started to develop miniature optical cavities based on optical fibers. This got us started on a new adventure, which is described elsewhere on this site.