Batch Optimization of Frequency-Modulated Pulses for Robust Two-Qubit Gates in Ion Chains

Journal Article (Journal Article)

Two-qubit gates in trapped-ion quantum computers are generated by applying spin-dependent forces that temporarily entangle the internal state of the ion with its motion. Laser pulses are carefully designed to generate a maximally entangling gate between the ions while minimizing any residual entanglement between the motion and the ion. The quality of the gates suffers when the actual experimental parameters differ from the ideal case. Here, we improve the robustness of frequency-modulated Mølmer-Sørensen gates to motional mode-frequency offsets by optimizing the average performance over a range of systematic errors using batch optimization. We then compare this method with frequency-modulated gates optimized for ideal parameters that include an analytic robustness condition. Numerical simulations show good performance up to 12 ions, and the method is experimentally demonstrated on a two-ion chain.

Full Text

Duke Authors

Cited Authors

  • Kang, M; Liang, Q; Zhang, B; Huang, S; Wang, Y; Fang, C; Kim, J; Brown, KR

Published Date

  • August 1, 2021

Published In

Volume / Issue

  • 16 / 2

Electronic International Standard Serial Number (EISSN)

  • 2331-7019

Digital Object Identifier (DOI)

  • 10.1103/PhysRevApplied.16.024039

Citation Source

  • Scopus