Speaker
Description
The molecular hydrogen ion is a promising candidate for the metrology of fundamental constants, as its rovibrational transition frequencies can be calculated to the few-10$^{-12}$ accuracy level [1]. Measuring the transition frequencies between the levels with similar precision will provide an independent determination of the proton to electron mass ratio $m_p$/$m_e$ and possibly of the proton radius. I will present our recent progress towards this goal. In particular, I will show experimental results of state-selective preparation of molecular hydrogen ions in the $v=0$ and $v=1$ states and a demonstration of our detection mechanism via photodissociation of the excited state. Very recently, we have embedded sympathetically cooled, state-selected H$_2^+$ ions in a cloud of laser cooled Be$^+$ ions and will soon attempt to observe the two-photon vibrational transition at 9.17µm [2].
[1] V.I. Korobov et al., PRL 118, 233001 (2017)
[2] F. Bielsa et al., Opt. Lett. 32, 1641 (2007)
