Evaluation and Suppression of Vibrational Noise for Cryogenic Surface Electrode Ion Traps

Cryogenic ion traps offer substantial advantages over their room-temperature counterparts, particularly in terms of stable ion confinement and cooling. However, this technological advancement has introduced a significant challenge, namely the generation of additional vibrational noise. This noise is pronounced during the compression and expansion phases of the Gifford-McMahon cycle refrigerator and stems from the mechanical operation of the cold head. The residual vibrational noise can modulate the Rabi oscillation frequency, thereby compromising the fidelity of the quantum logic gate. In this study, we quantitatively assess the impact of residual vibrational noise and introduce an innovative strategy for its mitigation. This strategy was designed to reduce superimposed potential fluctuations within a cryogenic surface electrode ion trap. The measured residual vibrational noise was used for real-time feedback control. Addressing the inverse determination of the compensating potential for a stable superimposed trapping potential is an inherently ill-posed problem considering known measurement noise results. By applying quadratic programming, we numerically calculated the optimal time series for the compensation potential. An ensemble of these compensation voltages was applied in real time to the static compensation electrodes. Although this method is in the theoretical stage, we believe that it can effectively suppress the translation induced by vibrational noise and foster the creation of a stable superimposed harmonic potential. The deployment of this technique is expected to substantially improve the accuracy of quantum operations, thereby fueling the evolution of quantum technologies.