Repozytorium publikacji - Politechnika Gdańska

Careful control of quantum states is a gateway to research in many areas of science such as quantum information, quantum-controlled chemistry, and astrophysical processes. Precise optical control of molecular ions remains a challenge due to the scarcity of suitable level schemes, and direct laser cooling has not yet been achieved for either positive or negative molecular ions. Using a cryogenic wire trap, we show how the internal quantum states of C2- anions can be manipulated using optical pumping and inelastic quenching collisions with H2 gas. We obtained optical pumping efficiencies of about 96% into the first vibrational level of C2- and determined the absolute inelastic rate coefficient from v=1 to 0 to be k_q = (3.2±0.2stat±1.3sys)×10−13  cm3/s at 20(3) K, over 3 orders of magnitude smaller than the capture limit. Reduced-dimensional quantum scattering calculations yield a small rate coefficient as well, but significantly larger than the experimental value. Using optical pumping and inelastic collisions, we also realized fluorescence imaging of negative molecular ions. Our work demonstrates high control of a cold ensemble of C2−, providing a solid foundation for future work on laser cooling of molecular ions.

Autorzy

• Markus Nötzold,
• Robert Wild,
• Christine Lochmann,
• Tanja Rahim,
• Sruthi Purushu Melath,
• Katrin Dulitz,
• Barry P. Mant,
• dr hab. Jan Franz link otwiera się w nowej karcie ,
• Francesco Antonio Gianturco,
• Roland Wester