Rotational state analysis of AlH+ by two-photon dissociation

Abstract

We perform ab initio calculations needed to predict the cross-section of an experimentally accessible (1 + 1 ′ ) resonance-enhanced multiphoton dissociation (REMPD) pathway in AlH + . Experimenting on AlH + ions held in a radiofrequency Paul trap, we confirm dissociation via this channel with analysis performed using time-of-flight mass spectrometry. We demonstrate the use of REMPD for rotational state analysis, and we measure the rotational distribution of trapped AlH + to be consistent with the expected thermal distribution. AlH + is a particularly interesting species for ion trap work because of its electronic level structure, which makes it amenable to proposals for rotational optical pumping, direct Doppler cooling, and single-molecule fluorescence detection. Potential applications of trapped AlH + include searches for time-varying constants, quantum information processing, and ultracold chemistry studies.

Design and characterization of a linear quadrupole ion trap for high-resolution Coulomb-crystal time-of-flight mass spectrometry

“…In all of these experiments, the ions are ejected radially from the trap. Seck et al coupled a LQT to a TOF-MS in which the ions are accelerated along the trap axis into the TOF-MS by applying a potential gradient using the endcaps of the ion trap [25]. The advantage of this setup is the separation of RF and highvoltage electrodes but the mass resolution for heavy ions in multi-component Coulomb crystals seems limited.…”

Frequency measurement of the 1 S 0 , F = 5 / 2 ↔ 3 P 1 , F = 7 / 2 transition of 27Al+ via quantum logic spectroscopy with 40Ca+

“…In experiments where the aluminium ion spends about half the time in the 3 P 0 clock state, we observe that Al + ions are replaced by molecular ions of mass m=28u on a time scale of about 15min. While we cannot unambiguously identify the ion species, it seems likely that Al + reacts with H 2 background gas molecules to form AlH + [42,43]. The resulting short time span for probing the clock transition in Al + , in combination with long Al + reloading times [32], prevented us from investigating the clock transition more thoroughly.…”

Sympathetic cooling of molecular ions with ultracold atoms

“…This resolution is sufficient to observe the individual isotopes of the trapped molecular ions and has allowed isotopically resolved chemistry and spectroscopy. Several other groups have also recently developed ToFMS capabilities using variations of the technique [66][67][68][69]. In addition to being a powerful measurement capability, we have found that in day-to-day operation the ToFMS provides an incredibly useful diagnostic tool.…”