Logo of the Physikalisch-Technische Bundesanstalt
Gateway for school

School/University

News

At PTB, optical thin-film materials for extreme ultraviolet lithography are systematically investigated at a wavelength of 13.5 nm. The optical constants (i.e., the refractive index and the extinction coefficient) have now been determined in the wavelength range between 10 nm and 20 nm with small uncertainties based on reflection measurements performed with synchrotron radiation.

[ more ]

In the past few years, increasing attention has been paid to the use of photon momenta in metrology, mainly in the field of radiometry, but also in force and mass measurement. This is due to the fact that photons behave like particles. When they collide with matter, the resulting momentum transfer can be used for measuring optical power or, vice versa, for generating a small force. This method of optical power measurement has now been accurately compared with well-established measurement procedures.

[ more ]
„Die Metrologie im Blick“

This year’s Helmholtz Prize is honoring two important contributions to physics, one relating to fundamental research and one to applied research, but both in the field of optics. The Helmholtz Prize is the most important award in the realm of metrology, the science of measurement. In the category of fundamental research, the prize goes to Soroosh Alighanbari and his colleagues in Prof. Schiller’s Research Group at the Heinrich Heine University Düsseldorf for the development of a new method of precision spectroscopy for exploring fundamental questions of physics. The Helmholtz Prize in the category of applied metrology has been won by Nathalie Picqué and Edoardo Vicentini of the Max Planck Institute of Quantum Optics in Garching. Their work has significantly expanded the possibilities of digital holography through the use of frequency combs. The awards ceremony for both prizes, each endowed with 20,000 euros, will be held on 12 May 2022...

[ more ]
WERAN-Berichtsübergabe

Drehfunkfeuer, also Navigationseinrichtungen, mit deren Hilfe Flugzeuge sicher navigieren, können durch Windenergieanlagen gestört werden. Deshalb muss die Störwirkung jeder geplanten Windenergieanlage von der Flugsicherung geprüft werden, wenn sie in einem gewissen Abstand zu einem Drehfunkfeuer errichtet werden soll. Dieser Abstand betrug bisher 15 km. Nach Abschluss zweier Forschungsprojekte empfehlen Wissenschaftler der Physikalisch-Technischen Bundesanstalt (PTB), diesen Abstand auf 6 km bis 7 km zu reduzieren. Damit würde sich die Wahrscheinlichkeit, dass neue Windenergieanlagen genehmigt werden, deutlich erhöhen. Die PTB übergab heute einen Forschungsbericht mit Erkenntnissen und Empfehlungen aus den Projekten an den Bundesverkehrsminister Dr. Volker Wissing und an den Bundeswirtschaftsminister und Vizekanzler Dr. Robert Habeck.

[ more ]
Coronaviren im Klassenzimmer

Welcher UV-C-Raumluftentkeimer nützt gegen Coronaviren? Und unter welchen Bedingungen? Und ist der Einsatz der Geräte sicher? Jetzt bringt eine neue Veröffentlichung des DIN mehr Sicherheit für Hersteller, potenzielle Anwender und Planer. Das umfangreiche Dokument wurde in nur wenigen Monaten von einer interdisziplinären Arbeitsgruppe im Fachausschuss „optische Strahlung“ des DIN erarbeitet, dessen Obmann Dr. Peter Sperfeld aus der Physikalisch-Technischen Bundesanstalt (PTB) ist. Die technische Spezifikation DIN/TS 67506 gilt für sogenannte UV-C-Sekundärluftgeräte mit geschlossener Bauart und aktiver Ventilation. Ein besonderes Augenmerk liegt auf der Sicherheit der Geräte, insbesondere für den Einsatz in Schulen oder Kindergärten

[ more ]

In the new joint project “ATIQ – Quantencomputer mit gespeicherten Ionen für Anwendungen” (quantum computers with stored ions for applications), 25 partners are aiming to develop the first generation of reliable and user-friendly quantum computer demonstrators with around-the-clock availability on the basis of ion trap technology within 30 months. To achieve this, the leading ion trap research groups at the universities of Hannover/Braunschweig, Siegen and Mainz have joined forces with research institutes (including PTB) and partners from industry. The project is being funded with 37.4 million euros by the Federal Ministry of Education and Research. (Contact: Christian Ospelkaus, +49 531 592-4740, Opens local program for sending emailchristian.ospelkaus(at)ptb.de)

[ more ]

Awards

Mathias Richter
Mathias Richter, Head of Division 7 Temperature and Synchrotron Radiation, was elected to the Council of the German Physical Society (DPG).

Piet Schmidt
Piet Schmidt, Head of the QUEST Institute at PTB, was appointed as a “Fellow of the American Physical Society” (APS) in recognition of his achievements in the development of quantum logic spectroscopy techniques and their application in high-precision measurements of optical transitions in atoms, molecules and highly charged ions.

Ekkehard Peik
Ekkehard Peik,Head of Department 4.4 Time and Frequency, received the “I. I. Rabi Award 2021” from the Institute of Electrical and Electronics Engineers (IEEE) in recognition of his achievements in the development of optical clocks and in tests of fundamental physics.

Uwe Sterr
Uwe Sterr, a staff member of Department 4.3 Quantum Optics and Unit of Length, received the “European Frequency and Time Award” (EFTA Award) in 2020...

[ more ]
Schematic representation of the measurement setup used for calibrating an MFM tip by means of a quantum sensor. The MFM tip (turquoise) generates a magnetic stray field which can be measured precisely over a single NV center (yellow) in a diamond substrate (blue). If the tip is scanned over the NV center, its stray field distribution is obtained – and thus quantum-accuracy information on its magnetic imaging properties is also gained.

A classical measurement system for measuring magnetic field distributions, which vary spatially on the nanometer scale, was calibrated by means of an atomic quantum sensor for the first time. This new calibration procedure does not depend on simplifying model assumptions and allows more reliable measurements of magnetic field distributions with high spatial resolution.

[ more ]
Die Teilchen sind innerhalb der goldenen Struktur in der Mitte gespeichert. Der Aufbau ist innen hohl und ähnelt einem Stapel von Unterlegscheiben unterschiedlicher Dicke. (Foto: Stefan F. Sämmer/JGU Mainz)

A new method to cool protons by means of laser-cooled ions – in this case, beryllium ions – has been successfully implemented for the first time worldwide. What is new about this method is that the cooling power can now be transmitted via a resonant electric circuit, covering an enhanced distance of 9 cm from one trap to the other. In this way, the proton in one of the traps can be cooled down to much lower temperatures than previously.

[ more ]
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 ultrastabile Laserfrequenzen aus den Metrologieinstituten per Glasfaser anderen Anwendern zugänglich gemacht werden können. Das internationale Forscherteam unter Leitung des britischen Metrologieinstitutes National Physical Laboratory (NPL) beweist darin, dass die extrem hohe Frequenzstabilität der eingesetzten ultrastabilen Laser auch bei der langen Reise zwischen ihren Instituten fast verlustfrei übertragen werden kann. Dies bestätigt die großen Hoffnungen, die auf dieser Art von Frequenztransfer liegen.

[ more ]