Speaker
Description
Due to the complexity of the internal energy structure of molecular ions, control of their quantum state poses serious challenges. Contrary to atomic counterparts, most molecules lack cycling optical transitions, which prevents standard state preparation and detection techniques based on optical pumping as well as direct translational cooling schemes. These challenging problems were recently solved for some diatomic molecular ions with quantum logic spectroscopy (QLS) techniques [1, 2, 3]. Here we report on the progress in extending control capabilities of the quantum state to polyatomic molecules using co-trapped calcium ions in a new cryogenic ion-trapping apparatus.
Our approach involves the preparation of the internal molecular state with a resonance-enhanced photoionization technique [4]. Co-trapped calcium ions serve a dual purpose - sympathetically cooling translational degrees of freedom of the molecular ion and employing quantum nondemolition state detection for the molecule. Employed QLS protocol relies on the state-dependent motional excitation of molecular ions exerted by an off-resonant optical lattice [1]. The cryogenic ion-trapping setup design and the current progress in its implementation will be discussed.
The realization of the described framework opens a route to studying chemical reactions of collisions on the state-to-state level and conducting quantum logic spectroscopy with polyatomic species.
[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] X. Tong, A. H. Winney, S. Willitsch, Physical Review Letters 2010, 105(14), 143001.
