Fig. 1: The schematic of experiment setup and experimental relative directions of the cooling laser, imaging system, and micromotion.
From: Two-dimensional cooling without repump laser beams through ion motional heating
a Voltage configuration on the linear quadrupole ion trap electrodes: DC is applied to four central electrodes (\({U}_{i}\)) and all the eight endcaps (\({U}_{{{\rm{end}}}}\)). RF and DC voltages are added to electrodes 2 and 3 with the expression \({U}_{i}+{U}_{{{\rm{rf}}}}\cos (\Omega t)\), where i corresponds to 1, 2, 3, or 4. The cooling lasers are positioned in the X-Z plane at a 45-degree angle to the X-axis, which is perpendicular to the Y-axis. b Side view of the LQT: The imaging system is oriented parallel to the Y-Z plane and perpendicular to the X-axis. Micromotion in the Y-direction is measurable by the imaging system, but not in the X-direction. The images linked by the red/black dashed lines are taken when the ions are displaced in the Y/X direction, respectively.
