Manipulating motion of trapped ions assisted by optical tweezers

Chen-Yu Lee¹, Kuan-Ting Lin¹, Guin-Dar Lin^1,2*

¹Center for Quantum Science and Engineering, and Department of Physics, National Taiwan University, Taipei City, Taiwan
²Physics Division, National Center for Theoretical Sciences, Taipei City, Taiwan

* Presenter:Guin-Dar Lin, email:guindarl@phys.ntu.edu.tw

Trapped ions have been demonstrated to be a very promising platform for quantum computing and simulation. Through laser mediated Coulomb interaction, one can establish the coupling between the atomic states and the motional degrees of freedom, the latter of which plays a role of quantum bus in usual quantum computing technology. In this work, we study the interesting dynamics while the motional spectrum of a large ion array is modified by optical tweezers. In particular, we apply optical tweezers to effectively pin one or a few consecutive ions, mimicking a partial mirror for acoustic waves. An acoustic cavity can be constructed by a pair of such mirrors sandwiching a subset of the ion array. The local modes can thus be studied with cavity loss rates controlled by the tweezer strength and the number of consecutive tweezered ions. Further, the cavity modes can be pumped or cooled by blue or red side-band transitions, respectively. For the former case, we study the phonon lasing behavior including the threshold, correlation function, and number statistics. For the latter case, we look into the cooling efficiency while side-band or electromagnetically-induced-transparent (EIT) cooling techniques are applied to the local modes.

Keywords: trapped ion, optical tweezers, laser cooling, phonon laser, quantum computing