On 11-June 2024, Thorsten Schumm gave a talk at the Institute of Science and Technology, Austria about his historic work on nuclear laser excitation. Thorsten visited Onur Hosten’s Quantum Sensing group, along with the Tulon Photonics spin-off founders. Tulon Photonics is proud to have Thorsten Schumm in its scientific advisory board. 

Thorsten heads the monumental endeavor of peering into the nucleus with a laser.  For the first time in history, the nucleus of an atom has been excited with a laser. Nuclear excited states are typically highly energetic, hence the only way to access them is by gamma rays or colliders such as at the LHC-CERN. 

To achieve this requires hunting for an atomic species with a low energy nuclear excitation. One that is low enough to be accessed by a laser. Out of all possible candidates, Thorium-229 presented the lowest possible nuclear excitable transition of ~ 8 eV. In optics, this would correspond to ~ 150 nm in wavelength.  This color corresponds to Vacuum Ultraviolet light (VUV). Rightly so, since even air absorbs VUV, thereby, vacuum environments are required for VUV light.  On the other hand, VUV laser light generation is in itself very difficult. 

To add to that difficulty, trapping the Thorium-229 isotopes in a host structure to allow optical interrogation is even more difficult.  To achieve this goal, the Thorium Nuclear Clock collaboration trapped Thorium-229 within CaF2 crystal. Calcium Flouride provides a perfect host for the Thorium atoms, as it is optically transparent.  In parallel to this, the VUV light is generated by 4-wave mixing; Three beams combine to create the 4th VUV laser beam.  

After more than a decade, Thorsten and his collaborators succeeded in exciting the nucleus of a Thorium-229 with a laser. This work pushes humanity towards the age of Nuclear Clocks. Nuclear clocks are 4-orders more accurate than optical atomic clocks.  It will also open up a new field of physics, Nuclear Quantum Optics.  To read more about this amazing work and its huge impact, check out the paper and links below.

Laser Excitation of the Th-229 Nucleus

J. Tiedau, M. V. Okhapkin, K. Zhang, J. Thielking, G. Zitzer, E. Peik, F. Schaden, T. Pronebner, I. Morawetz, L. Toscani De Col, F. Schneider, A. Leitner, M. Pressler, G. A. Kazakov, K. Beeks, T. Sikorsky, and T. Schumm

Phys. Rev. Lett. 132, 182501 – Published 29 April 2024

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.182501

Shedding Light on the Thorium-229 Nuclear Clock Isomer

Peter Thirolf

Department of Physics, Ludwig-Maximilians-Universität München, Munich, Germany

April 29, 2024• Physics 17, 71

https://physics.aps.org/articles/v17/71

Thorsten’s Quantum Metrology at TU Wien webpage:

https://www.tuwien.at/phy/ati/quantenmetrologie

Thorium Nuclear Clock 

https://thoriumclock.eu/

Published: 11-June-2024

Onur Hosten, the chief scientific adviser of Tulon Photonics, was recently featured in Austrian news.  Onur is the co-inventor of the Tulon Photonics core IP.  He initiated the idea of modulation-free laser frequency stabilization, to which he and Fritz religiously applied in various cases during the Pandemic.

To read the original news article, ERC news and more about Onur's work, check below. 

New Article:

Onur Hosten from the Institute of Science and Technology Austria tackles the really big questions: How does gravity behave in the quantum realm? Check it out!  

 QUANTENGRAVITATION Neuer Versuch, Quantenphysik und Relativitätstheorie zu vereinen

ERC News:

The European Research Council (ERC) has selected the proposals of four ISTA scientists for #funding with two million Euros each.

Onur Hosten's Research Group at ISTA

https://hostenlab.pages.ist.ac.at/