European Conference on Trapped Ions (ECTI)

I will present work on laser cooling a trapped-ion oscillator based on sequences of spin-state dependent displacements followed by spin repumping. For a thermal state with mean occupation $\overline{n}\gg 1$ the method attains a reduction of 0.632 of the initial thermal oscillator occupation for two repumps of the spin state. We demonstrate the motion using a single calcium ion, and illustrate its advantages and limitations. To increase robustness to imperfections, we have recently been working to implement the method spin-state dependent displacements with laser pulses of very different intensity, requiring integrating phase tracking into our FPGA hardware to work in real-time for flexible sequence generation and deployment. We will also present an overview of upgrades to the control system underlying all the experiments in the ETH Zurich group.