Speaker
Description
Molecular ions can be utilized to probe fundamental theories [1] as well as for cold chemical reactions and collision studies. Unlike their atomic counterparts, molecules lack cycling optical transitions, which, along with the overall complexity of their internal energy level structure, significantly complicate cooling and internal state control. These challenges were successfully solved for a range of diatomic molecular ions using quantum logic spectroscopy (QLS) [2-4]. Polyatomic molecules exhibit a new set of properties, such as isomerism and chirality, which may be utilized in tests of fundamental physical theories [5].
Building on these advances, we aim to extend QLS methods to $H_2O^+$ molecular ions. Molecules are ionized using a 2+1 resonant-enhanced multiphoton photoionization technique [6] and sympathetically cooled by a crystal of laser-cooled $Ca^+$ ions. The internal state of the molecule is prepared by thermalization with a cryogenic environment. Then the rovibrational state of the $H_2O^+$ is detected non-destructively using a single co-trapped $Ca^+$ ion by exerting a state-dependent off-resonant optical dipole force on the molecule and reading out the resulting motional excitation of the ion pair.
Here we discuss the characterization of a cryogenic ion trapping apparatus, which is used for trapping and sympathetic cooling of single water molecular ions, as well as the current progress towards the state detection of water ions in our setup.
- T. Roussy et al., Science 381, 6653 (2023)
- M. Sinhal et al., Science 367, 1213 (2020).
- F. Wolf et al., Nature 530, 457 (2016).
- C.-W. Chou et al., Nature 545, 203 (2017).
- M. Quack et al., Annu. Rev. Phys. Chem. 59, 741 (2008).
- X. Tong et al., Phys. Rev. Lett. 105, 143001 (2010).
| Academic level | PhD student |
|---|