Programmable Global Ising Dynamics and Predistorted Gate Control in Trapped Ions

Abstract

Trapped-ion quantum computers provide a highly controllable platform for simulating complex quantum systems. In our recent work [1], we demonstrated a programmable global-drive protocol that realizes multi-tone entangling gates using homogeneously applied laser fields. This enabled the experimental simulation of a four-qubit Ising spin ring with antiperiodic boundary conditions, fully reconstructing the underlying Hamiltonian and demonstrating high-fidelity programmable dynamics using a shallow, global-only control scheme.

As quantum algorithms grow more complex, such global multi-tone gates must operate at high power and spectral precision. However, acousto-optic modulators and amplifiers introduce nonlinear distortions that degrade the fidelity of the applied waveform. To address this, we are developing a digital predistortion (DPD) technique that compensates for device nonlinearity in a feed-forward manner.

While DPD has not yet been applied to gate operations, we present preliminary spectral measurements using photodiode detection that demonstrate improved suppression of intermodulation tones. These results pave the way for combining DPD with advanced multi-tone gate schemes [2,3] to enable faster, higher-fidelity gates with higher utilization of the available optical power.

Our poster presents a unified perspective: global entangling gates reduce control complexity for quantum simulation, and DPD enables faster gates without sacrificing fidelity.

References

• [1] Y. Shapira et al., Phys. Rev. Lett. 134, 010602 (2025)
• [2] Y. Shapira et al., Phys. Rev. Lett. 121, 180502 (2018)
• [3] Y. Shapira et al., Phys. Rev. A 101, 032330 (2020)