High-Precision Penning Trap Spectroscopy of the Ground State Spin Structure of ${\mathrm{HD}}^{+}$

Author(s): Charlotte M. König, Matthew Bohman, Fabian Heiße, Jonathan Morgner, Tim Sailer, Bingsheng Tu, Klaus Blaum, Sven Sturm, Dimitar Bakalov, Hugo D. Nogueira, Jean-Philippe Karr, Ossama Kullie, and Stephan Schiller Precise spectroscopy of a simple molecular ion opens a new path toward stringent tests of quantum electrodynamics. [Phys. Rev. Lett. 136, 143002] Published Wed Apr 08, 2026