Speaker
Description
Due to the complexity of their internal energy level structure, controlling molecules' internal states presents a significant challenge. Most molecular ions lack closed optical cycling transitions, which prevents standard state preparation and detection techniques routinely exploited in the atomic community, as well as direct laser cooling techniques. These challenges were recently tackled for some diatomic molecules employing quantum logic spectroscopy techniques (QLS) [1-3]. Unlike diatomic species, polyatomic ones exhibit new properties such as isomerism, chirality, and parity doublet states, which may be employed in tests of fundamental physical theories [4].
We aim to extend QLS methods to polyatomic molecular ions. Our approach involves the state preparation of molecular ions using a resonant-enhanced multiphoton photoionization technique [5]. The state-prepared molecular ion is trapped and sympathetically cooled inside a crystal of laser-cooled Ca ions. The state of the molecular ion is then detected 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 crystal.
Here we discuss the progress in the construction and initial characterization of a cryogenic ion trapping setup, which will be used for trapping and QLS of polyatomic molecular ions, as well as for cold chemistry and collision studies on a state-to-state level.
[1] M. Sinhal, Z. Meir, K. Najafian, G. Hegi, S. Willitsch, Science 2020, 367(6483), 1213.
[2] F. Wolf, Y. Wan, J. C. Heip, F. Gebert, C. Shi, P. O. Schmidt, Nature 2016, 530(7591), 457-460.
[3] C. W. Chou, C. Kurz, D. B. Hume, P. N. Plessow, D. R. Leibrandt, D. Leibfried, Nature 2017, 545(7653), 203-207.
[4] L. Anderegg, N. B. Vilas, C. Hallas, P. Robichaud, A. Jadbabaie, J. M. Doyle, N. R. Hutzler, Science 2023, 382(6671), 665-668.
[5] X. Tong, A. H. Winney, S. Willitsch, Physical Review Letters 2010, 105(14), 143001.
