Supression of differential light shifts in hyperfine ¹⁷¹Yb⁺ qubits

Laser-based gates in trapped ion quantum computers can induce differential light shifts that dephase qubits, limiting coherence lifetimes. Magnetic-field-induced vector light shifts are polarization dependent however, such that with appropriate choice of polarization for a given magnetic field, this differential light shift may be eliminated. Used commonly in optical dipole traps, this "magic" polarization technique is relatively simple to implement, and has been applied to other trapped ion species [1]. We demonstrate in the ground-state hyperfine qubit of ¹⁷¹Yb⁺ that it is possible to supress the differential light shift at typical values of the static bias magnetic field by adjusting the gate laser polarization.

[1] Samuel R. Vizvary, et al. Eliminating qubit type cross-talk in the omg protocol, 2023. arXiv.