Under an ERC Advanced Grant, we perform precision spectroscopy of the simplest molecule. We compare the transition frequencies with theoretical predictions. This opens up important topics: the determination of fundamental constants, a test of the wave properties of quantum matter, a search for exotic forces, so-called o"fifth forces". For more information, see Alighanbari et al 2020 and Kortunov et al 2021. In the framework of the project we also develope new techniques for spectroscopy of ions in traps.
In collaboration with our partners Dr. C. Lisdat (PTB Braunschweig) and Prof. K. Bongs (U. Birmingham), we have developed a transportable optical atomic clock based on ultracold strontium atoms [Origlia et al 2018]. It is currently undergoing an upgrade, with an improved clock laser, a transportable Ti:Sapphire lattice laser, and a transportable frequency comb. We intend to operate the clock in the near future at the fundamental station Wettzell (collaboration with Prof. U. Schreiber, TUM) and to exchange time signals with the ISS experiment ACES.
In a second project we are developing a transportable ytterbium lattice clock.
These projects will profit from technology developments we are pursuing in the framework of a BMBF-funded consortium called "ISABELLA" (coordinator: Dr. Sacher, Sacher Lasertechnik GmbH).
We search for temporal oscillations of fundamental constants with spectroscopic experiments. Such oscillations are a conceivable consequence of a quantum mechanical field of dark matter parts. In cooperation with the University of Mainz we demonstrated a molecular spectroscopy approach [Oswald et al - arxiv].