MPQ Colloquium: Rotating molecules and fundamental constants

Jun 26

When:     Tuesday, June 26, 2018, 2:30 pm
Loaction: MPQ Garching, New Lecture Hall, Room B 0.32

Prof. S. Schiller,  Quantum Optics and Relativity Group, Institute for Experimental Physics, Heinrich-Heine-Universität Düsseldorf, will talk about "Rotating molecules and fundamental constants".


Molecules provide exciting opportunities for precision measurements - significantly extending those offered by atoms.In recent years, it has become possible to manipulate molecules in more and more powerful ways, especially cooling them to the millikelvin range and lower and trapping them. This enables precision spectroscopic studies.

Our own work focuses on the second-simplest existing molecule: HD+, one member of the family of molecular hydrogen ions (MHI). This three-body quantum system is sufficiently simple that it can be dealt with by ab initio theory, yet it still poses a significant challenge when it comes to high-precision predictions.

In order to test the predictions and to determine some key fundamental constants of atomic physics using this molecule, we have developed a novel technique for rotational spectroscopy, which achieves the Lamb-Dicke regime [1].

This enabled us to observe ultra-narrow rotational transitions, and to determine their frequency with an uncertainty smaller than the current theoretical uncertainty. The comparison between experiment and theory allows deducing a value of the proton mass with an uncertainty 3 times lower than in previous molecular spectroscopic experiments.

The presentation will outline the opportunities that precision spectroscopy of MHIs offers, describe our experimental technique, the results and the potential for further improvement.


[1] S. Alighanbari, et al. Nature Physics, in press (2018); arXiv:1802.03208v1


For more information visit the MPQ weppage.