Figure 1

Micrograph of the ion trap, showing radio-frequency (rf) electrodes and control electrodes. The red sphere indicates the approximate ion position in the $x-y$ plane. Also shown are the directions of the static magnetic field $B_0$ and of the microwave current used to drive hyperfine transitions. (Inset) Energy level diagram (not to scale) of the $2s{}^2{S}_{1/2}$ hyperfine states in ${}^9{\mathrm{Be}}^{+}$. Blue (two leftmost) dashed lines indicate the transitions used to prepare and to measure $|\downarrow \rangle$. The solid black line indicates the qubit transition, and the red (rightmost) dashed line indicates one of the transitions used to shelve $|\uparrow \rangle$ into a dark state.Reuse & Permissions

Figure 2

Results of the single-qubit benchmarking experiments. (a) Histogram of sequences of a given length with a given fidelity. Fidelity is discretized to 0.01 precision because 100 experiments were performed for each sequence. (b) Mean fidelity for each sequence length with error bars. The black trace is a least-squares fit to Eq. (1) yielding an EPG of $2.0\left(2\right)\times {10}^{-5}$. (Inset) Summed histogram of bright and dark calibration experiments with a red line indicating the detection threshold.Reuse & Permissions

Figure 3

Changes in (a) qubit transition frequency and (b) $\pi /2$ duration during the benchmarking experiments. Change is defined as the difference between the recalibrated value and the first calibration. Typical transition frequencies and $\pi /2$ durations are approximately 1.250 7385 GHz and $20.50\mu \mathrm{s}$, respectively.Reuse & Permissions