Research

Super Conducting Atom Chip

Superconductor technology combined with atom optical systems will allow a new generation of fundamental experiments and novel applications possibly reaching to the pairing of quantum solid-state devices with neutral atoms on the quantum mechanical level. In particular, the enormous capability of superconducting devices paired with atom optics is especially promisingutilizing microstructured surface traps. For example, these can be used for quantum state transfer between solid-state and atomic systems or quantum information processing. Microstructured surface trapping and manipulation devices, so-called ‘atom chips’, have proven their great capability and flexibility in the field of ultra-cold atom experiments over the last few years. These elements which allow the generation of steep trapping potentials use current carrying wires or permanent magnetic structures as well as micro-optical devices. They have, for example, been used for guiding and transportation potentials of various kinds as well as for the generation of quantum-degenerate gases. Additionally, the manipulation of neutral atoms with microstructured elements is a promising approach for realizing systems suitable for quantum information processing.

We designed a ceramic-based high-temperature superconductor (HTS) atom interferometer chip structure using a persistent current loop to overcome limitations which normal conductors face. In combination with two superconducting wires carrying an externally supplied current, an atom guide is realized. Along the atomic propagation direction this guide is split into two arms. These arms separate the atoms further and are afterwards redirected to merge the atoms again. This realizes a structure similar to a Mach–Zehnder interferometer
The Lemon
This is a novel interferometer-type guiding structure based on a closed superconducting loop. The guiding potential has been optimized with respect to critical parameters near the splitting regions of matter waves. The interferometer-type guide has the potential to overcome limitations which current room temperature atom chip devices are facing. One example is the fragmentation of atomic clouds close to the chip surface. Currently, numerical simulations of the propagation of atomic matter waves in the presented guiding structures are being performed for a further optimization of the second generation superconducting chip devices. At present, the superconducting atom chip is integrated into our cryogenic experimental setup for the generation of quantum-degenerate gases. The enormous potential offered by the combination of superconducting solid-state systems with neutral atoms will allow a variety of novel experiments, which will not be limited to HTS only. These are, for example, the probing of vortices in superconducting films with neutral atoms, the coupling of the magnetic moment of ultra-cold atoms to superconducting quantum interference devices and the quantum state transfer between the solid state and atomic quantum systems. However, this type of experiments faces severe technical challenges which will partially be evaluated with the presented system.

Paper