Micromotion Reduction and Barium-Ytterbium Ion Chains

The purpose of this REU project was to compensate for micromotion to reduce ion temperature and to trap and retain barium-ytterbium ion chains. Having cold ion chains allows us to implement quantum gates, which is a necessary component to any quantum computer. Micromotion is a constant issue that frequently needs to be compensated for because the electric fields within our trap are prone to drifting. We could adjust for it visually and we could “measure” it by checking how well we were driving the ion from S1 /2 → D5 /2 energy levels (used a 1762 nm laser for this transition). After compensating micromotion we were able to trap mixed ion chains and retain them for relatively long times.