Characterization of micromotion induced by RF phase shift with photon correlation detection in a Paul trap

Abstract: Trapped ions in a Paul trap can experience micromotion on top of the wanted secular motion.Micromotion can for example cause Doppler shifts in spectroscopy measurements, making it important to know the amplitude of the motion. In this master thesis we use the correlation between RF driving the trap and photons emitted by a single Beryllium ion during the fluorescence detection to determine the micromotion. This method also allows us to investigate the effect on micromotion from a phase mismatch between RF electrodes. The photon correlation method is compared to measuring the micromotion by taking the ratio between the micromotion sideband and the carrier transition, and also to a simulation of the residual RF fields in the trap by a finite element method. Finally, we vary the path length of RF lines, to tune the phase on individual RF electrodes. The result is that the phase mismatch effect is more than an order of magnitude less than expected from theory.