Freiburg 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 19: Ultracold Molecules and Precision Spectroscopy (joint session MO/Q)
Q 19.4: Talk
Tuesday, March 12, 2024, 11:45–12:00, HS 3044
First laser spectroscopy of a rovibrational transition in the molecular hydrogen ion H2+ — •Magnus Roman Schenkel, Soroosh Alighanbari, and Stephan Schiller — Institut für Experimentalphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
The molecular hydrogen ion H2+ is the simplest molecule and has been the subject of innumerous theoretical studies, culminating in highly precise predictions of its level energies [1]. Comparisons of these predictions and measured transition frequencies would offer excellent opportunities in fundamental physics that go beyond the results achieved with the related HD+ [2]: a direct determination of the proton-electron mass ratio. In this work we report the first vibrational laser spectroscopy of para-H2+ between low-lying rovibrational levels [3]. We observed a first overtone electric quadrupole (E2) transition at 2.4 µm and determined its spin-averaged frequency with 1.2×10−8 fractional uncertainty, finding agreement with theory. By using HD+ as a test molecule, we also show that E2 spectroscopy is possible with 1×10−12 uncertainty. This demonstrates that determining mp/me spectroscopically with competitive accuracy is a realistic prospect.
This work has received funding from DFG and NRW via grants INST-208/774-1 FUGG, INST-208/796-1 FUGG and from the ERC (grant No. 786306, *PREMOL*).
[1] V. I. Korobov and J.-P. Karr, Phys. Rev. A 104, 032806 (2021).
[2] S. Alighanbari et al., Nat. Phys. 19, 1263 (2023).
[3] M. R. Schenkel et al., Nat. Phys., to appear (2023).
Keywords: Spektroskopie; Fundamentalforschung; Kalte und kontrollierte Moleküle; Paul-Falle; Wasserstoffmolekülionen