BioHyTec: Biohybride Technologien in der Hauptstadtregion – Kompetenzbildung und Aufbau einer regionalen Wertschöpfungskette

Das Bundesministerium für Bildung und Forschung (BMBF) startete 1999 mit dem InnoRegio-Wettbewerb eine neuartige Förderinitiative unter der Leitidee „Innovative Impulse in den Neuen Ländern“. In zahlreichen Regionen wurden Aktivitäten in Gang gesetzt, um neue Formen der Zusammenarbeit von Menschen aus den unterschiedlichsten Bereichen zu entwickeln und damit die Wertschöpfung und Wettbewerbsfähigkeit in den ostdeutschen Regionen zu erhöhen. An dieser Ausschreibung nahmen in der Anfangsphase 444 Bewerberregionen teil. Nach der ersten Jury-Sitzung im Oktober 1999 wurden 50 InnoRegios ausgewählt, in einer Entwicklungsphase ihre Kernkompetenzen herauszufiltern und tragfähige Innovationskonzepte zu erarbeiten. Mit der zweiten Jury-Sitzung im Herbst 2000 fiel der Startschuss zur Umsetzungsphase. Zur Zeit werden vom BMBF 23 InnoRegios in den Neuen Ländern gefördert

Realisation eines Materiewelleninterferometers für Moleküle und neue Möglichkeiten zur Beobachtung von Atom-Molekül-Stößen

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8E-17 fractional laser frequency instability with a long room-temperature cavity

We present a laser system based on a 48 cm long optical glass resonator. The large size requires a sophisticated thermal control and optimized mounting design. A self balancing mounting was essential to reliably reach sensitivities to acceleration of below $\Delta \nu / \nu$ < 2E-10 /g in all directions. Furthermore, fiber noise cancellations from a common reference point near the laser diode to the cavity mirror and to additional user points (Sr clock and frequency comb) are implemented. Through comparison to other cavity-stabilized lasers and to a strontium lattice clock an instability of below 1E-16 at averaging times from 1 s to 1000 s is revealed

Achromatic, planar Fresnel-Reflector for a Single-beam Magneto-optical Trap

We present a novel achromatic, planar, periodic mirror structure for single-beam magneto-optical trapping and demonstrate its use in first- and second-stage cooling and trapping for different isotopes of strontium. We refer to it as Fresnel MOT as the structure is inspired by Fresnel lenses. By design, it avoids many of the problems that arise for multi-color cooling using planar structures based on diffraction gratings, which have been the dominant planar structures to be used for single-beam trapping thus far. In addition to a complex design process and cost-intensive fabrication, diffraction gratings suffer from their inherent chromaticity, which causes different axial displacements of trap volumes for the different wavelengths and necessitates tradeoffs in their diffraction properties and achievable trap depths. In contrast, the Fresnel reflector structure presented here is a versatile, easy-to-manufacture device that combines achromatic beam steering with the advantages of a planar architecture. It enables miniaturizing trapping systems for alkaline-earth-like atoms with multiple cooling transitions as well as multi-species trapping in the ideal tetrahedral configuration and within the same volume above the structure. Our design presents a novel approach for the miniaturization of cold-atom systems based on single-beam MOTs and enables the widespread adoption of these systems.Comment: 7 pages, 6 figure

Quantum engineering for optical clocks

Atomic clocks known as optical clocks are more accurate and stable than current timekeepers. Two quantum-engineering approaches could improve the performance of optical clocks even further and extend their applications

Prospects and challenges for squeezing-enhanced optical atomic clocks

Optical atomic clocks are a driving force for precision measurements due to the high accuracy and stability demonstrated in recent years. While further improvements to the stability have been envisioned by using entangled atoms, squeezing the quantum mechanical projection noise, evaluating the overall gain must incorporate essential features of an atomic clock. Here, we investigate the benefits of spin squeezed states for clocks operated with typical Brownian frequency noise-limited laser sources. Based on an analytic model of the closed servo-loop of an optical atomic clock, we report here quantitative predictions on the optimal clock stability for a given dead time and laser noise. Our analytic predictions are in good agreement with numerical simulations of the closed servo-loop. We find that for usual cyclic Ramsey interrogation of single atomic ensembles with dead time, even with the current most stable lasers spin squeezing can only improve the clock stability for ensembles below a critical atom number of about one thousand in an optical Sr lattice clock. Even with a future improvement of the laser performance by one order of magnitude the critical atom number still remains below 100,000. In contrast, clocks based on smaller, non-scalable ensembles, such as ion clocks, can already benefit from squeezed states with current clock lasers. © 2020, The Author(s)