Well-controlled motional states of molecular ions are a prerequisite for applications such as quantum information processing and precision measurements. In this talk, we'll report our experimental results on adiabatic control of motional states of a calcium oxide ion (CaO⁺) in a linear RF trap. In our experiment, we co-trap a CaO⁺ with a calcium ion (Ca⁺), and sympathetically cool CaO⁺'s axial motion to the ground motional states via sideband cooling Ca⁺. Then we adiabatically ramp the secular frequency and investigate the change of the motional states. This work is the first step towards observing the interaction of the CaO⁺ dipole with its motion^[1,2].

 

[1] W.C. Campbell and E.R. Hudson. Dipole-Phonon Quantum Logic with Trapped Polar Molecular Ions. Phys. Rev. Lett. 125, 120501 (2020).

[2] M. Mills, H. Wu, E.C. Reed, L. Qi, K.R. Brown, C. Schneider, M.C. Heaven, W.C. Campbell and E.R. Hudson. Dipole–phonon quantum logic with alkaline-earth monoxide and monosulfide cations. Phys. Chem. Chem. Phys. 22, 24964-24973 (2020).