Institute for Experimental Physics

In the teams of the institute, we work on experimental quantum optics and on quantum metrology, a subfield of quantum technology. We investigate how we can prepare fundamental particles, atoms and molecules in special states, by means of cryogencis and lasers, and how to use the particles for addressing questions in fundamental physics.

These include:

Are the established symmetries of Physics (CPT symmetry, Lorentz Invariance) exactly or only approximately valid?
Are there other forces besides the four known forces of nature?
What is the nature of dark matter?
Is standard quantum mechanics theory complete?
How can molecules with extremely low kinetic energy be produced?
How do atoms interact in highly excited states?

Answering these questions requires, in particular, developing and refining new experimental techniques.

2024/11: Ph.D. students Magnus Schenkel und Victor Vogt present a unique laser-based spectroscopy system. For the first time it is feasible to perform spectroscopy over a wide spectral range in the infrared domain with high power and excellent frequency accuracy.

2024/04: In a joint publication, Prof. J.-Ph. Karr (Paris) and Prof. Schiller predict that it should be possible to achieve an important improvement in several fundamental constants, by pushing the laser spectroscopy of the molecular hydrogen ions to a new level

2024/04: To an engaged audience at the Sternwarte Neanderhöhe Hochdahl in Erkrath, Prof. Schiller gives a talk on Dark Matter and Laboratory Searches for it

2024/03: Ph.D. students V. Vogt and M. Schenkel present their work at the spring meeting of the German Physical Society in Freiburg. Clear and convincing talks!

2024/01: A new window on the simplest molecule: first laser spectroscopy of a transition in H₂⁺. Our results have been commented on here

2023/11: Successful extension of the Max-Planck / RIKEN / PTB Center for Time, Constants and Fundamental Symmetries

2023/09: Our review article on the precision spectroscopy of molecular hydrogen ions has appeared

2023/06: We extend one-photon sub-Doppler spectroscopy of trapped ion ensembles to transitions with near-infrared wavelength and thereby perform one of the most precise tests of quantum theory.

2022/11: Christian Wellers receives the degree "Dr. rer. nat." after passing his oral examination. A large audience attended his presentation on the development and characterization of an ion trap apparatus for spectroscopy of single atomic and molecular ions.  We are happy that he successfully completed a most difficult project!

2022/11: Dr. Stefan Ulmer from RIKEN (Japan) and CERN (Switzerland) joins the Faculty of Physics of HHU. Welcome to our university!

2022/10: Jianwei Shen obtains the Ph.D. degree, based on his research on optical and THz spectroscopy of trapped ions.

2022/05: Michael Hansen passes the Ph.D. oral examination on the topic "Frequency metrology tools for high-precision spectroscopy of molecular hydrogen ions". It is the first live oral since the pandemy. Congratulations!

2022/05:  Team "Ion trap I" (S. Alighanbari, G. Giri, I. Kortunov, M. Schenkel, S. Schiller) is awarded this year's Helmholtz-Prize of the Helmholtz-Fonds during a celebration in Physikzentrum Bad Honnef. It was followed by a river trip on the ship "Moby Dick". The prize carries a 20.000 € cheque.

2021/12: R. Oswald, Victor Vogt and A. Nevsky set new limits for the interaction between dark matter and common matter.

2021/12: Doctoral student Rene Oswald and A. Nevsky demonstrate a novel spectroscopy technique for ions in solids.

2021/11: For the first time, a single molecular hydrogen ion is trapped and cooled in a controlled way in a radio-frequency trap (Christian Wellers, Magnus Schenkel et al.).

2021/08: Eugen Wiens graduates with a dissertation on cryogenic optical resonators. Congratulations!

2021/08: Doctoral student Ivan Kortunov discovers ultra-narrow infrared transitions in sympathetically cooled ions and realises a high-precision measurement of the proton-electron mass ratio.

2020/08: Soroosh Alighanbari obtains his Ph.D. degree summa cum laude.

2020/06:    D. Bakalov (INRNE, Sofia) and his team present, with our contribution, the accurate theory of the hyperfine structure of the deuterium molecular ion

2020/05:    We succeeded in performing the most precise determination of the proton-electron mass ratio by spectroscopy of HD⁺

2020/04:    E. Wiens presents the complete characterization of a compact, vibration-insensitive silicon resonator operated at 3 K

2019/05:   Interview with Prof. Schiller about the ERC project "PREMOL" (in German, starts at 1:50 min)

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