Rotating molecules and fundamental constants (Prof. S. Schiller)
14:30 - 15:30
Prof. Dr. Stephan Schiller
Quantum Optics and Relativity Group, Institute for Experimental Physics, Heinrich-Heine-Universität Düsseldorf
New Lecture Hall, Room B 0.32
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
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 .
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.
S. Alighanbari, et al. Nature Physics, in press (2018); arXiv:1802.03208v1