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Glasfaser-Netzwerk

Zwischen Deutschland, England und Frankreich existiert eine Art Autobahn für optische Frequenzen. Das Glasfasernetz dient bisher zum Vergleich von Frequenzen zwischen Metrologieinstituten, etwa aus optischen Atomuhren. Nun haben die Autoren einer Studie unter Beteiligung der Physikalisch-Technischen Bundesanstalt (PTB), die in der aktuellen Ausgabe von Nature Communications erscheint, gezeigt, wie...

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Laser cooling

Laser beams can do more than just heat things up; they can cool them down too. That is nothing new for physicists who have devoted themselves to precision spectroscopy and the development of optical atomic clocks. But what is new is the extremely low temperature that researchers at the QUEST Institute at the Physikalisch-Technische Bundesanstalt (PTB) have been able to reach with their highly...

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Random-Walk-Verfahren

Manipulating individual electrons with the goal of employing quantum effects offers new possibilities and greater precision in electronics. However, these single-electron circuits are governed by the laws of quantum mechanics, meaning that deviations from error-free operation still occur – albeit (in the best possible scenario) only very rarely. Thus, insights into both the physical origin the and...

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Einzelionenfalle der PTB

Optische Atomuhren sollen die ungestörte Frequenz eines atomaren Übergangs realisieren. Konsequente Weiterentwicklungen solcher Atomuhren machen sie zu den genauesten Messinstrumenten, die heutzutage zur Verfügung stehen. Ein Forschungsschwerpunkt bildet dabei die Entwicklung von Verfahren zur genauen Kontrolle oder Eliminierung von Frequenzverschiebungen durch äußere Störeinflüsse. In der...

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Dielektrizitätskonstanten-Gasthermometer

Scientists from the Physikalisch-Technische Bundesanstalt (PTB) have implemented a novel pressure measurement method, quasi as a byproduct of the work on the "new" kelvin. In addition to being new, this procedure is a primary method, i.e. it only depends on natural constants. As an independent method, it can be used to check the most accurate pressure gauges, for which PTB is known as the world...

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Ein Wissenschaftler-Team der Physikalisch-Technische Bundesanstalt (PTB) erhält am 8. November 2019 den Technologietransferpreis der Industrie- und Handelskammer Braunschweig für die gelungene Weitergabe einer mess- und fertigungstechnischen Meisterleistung aus der Forschung in die Industrie. Die Rede ist von hochreinen, extrem runden Siliziumkugeln, die die neue Definition des Kilogramms...

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Das Logo des neuen Zentrums

In the new MPG-PTB-RIKEN Centre for Time, Constants and Fundamental Symmetries, experimental physicists with a passion for precision will jointly tackle forefront topics in fundamental physics such as the question for the constancy in time of natural constants or the subtle differences between matter and antimatter. This new initiative started on January 1, 2019; the official opening ceremony will...

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Laseraufbau

The nucleus of thorium-229 possesses a property that is unique among all known nuclides: It should be possible to excite it with ultraviolet light. To date, little has been known about the low-energy state of the Th-229 nucleus that is responsible for this property. Together with their colleagues from Munich and Mainz, researchers at the Physikalisch-Technische Bundesanstalt (PTB) have now...

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Laser-Aufbauten der optischen Aluminiumuhr

The Physikalisch-Technische Bundesanstalt (PTB) is known for providing time e.g. for radio-controlled clocks. For this purpose, it operates some of the best cesium atomic clocks in the world. At the same time, PTB is already developing various atomic clocks of the next generation. These clocks are no longer based on a microwave transition in cesium, but they rather operate with other atoms that...

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