Fig. 1: Experimental setup, energy levels and experimental sequence.
a Cross-section view of the Be and coupling traps. Electrodes are cylinder-shaped and made of gold-plated oxygen-free high thermal conductivity copper. They have an inner diameter of 9 mm for the Be trap and 8 mm for the coupling trap. The single laser-cooled 9Be+ion is transported back and forth over a distance of 22.3 mm from electrode 3 (E3) in the Be trap to electrode 9 (E9) in the coupling trap. Each electrode is equipped with a 3-stage low-pass RC filter to minimize electrical noise. The trap electrodes are color-coded for identification. b Relevant internal level scheme of 9Be+in a 5 Tesla magnetic field. The cooling and detection (D) as well as the repumper transition (R) are represented by light and dark blue arrows, respectively. The Raman transitions are depicted by dark and light green arrows for Raman transitions 1 (R1) and 2 (R2), respectively. Energy levels are not to scale. c Simplified schematic of the trap voltage electronics. The electrode voltages, generated by an arbitrary waveform generator (AWG), are amplified and applied to the electrodes at cryogenic temperatures using filters at different temperature stages (room temperature, 60 K and 5 K). R1, R2 and R3 are 5.0 kΩ, 5.2 kΩ and 7.1 kΩ, respectively. C1, C2 and C3 are 4.8 nF. d Measurement cycle scheme, where tcool and ttp are the cooling and transport times, respectively.
