Efficient numerical approach to high-fidelity phase-modulated gates in long chains of trapped ions

Sheng-Chen Liu, Lin Cheng, Gui-Zhong Yao, Ying-Xiang Wang, and Liang-You Peng
Phys. Rev. E 107, 035304 – Published 22 March 2023

Abstract

Almost every quantum circuit is built with two-qubit gates in the current stage, which are crucial to the quantum computing in any platform. The entangling gates based on Mølmer-Sørensen schemes are widely exploited in the trapped-ion system, with the utilization of the collective motional modes of ions and two laser-controlled internal states, which are served as qubits. The key to realize high-fidelity and robust gates is the minimization of the entanglement between the qubits and the motional modes under various sources of errors after the gate operation. In this work, we propose an efficient numerical method to search high-quality solutions for phase-modulated pulses. Instead of directly optimizing a cost function, which contains the fidelity and the robustness of the gates, we convert the problem to the combination of linear algebra and the solution to quadratic equations. Once a solution with the gate fidelity of 1 is found, the laser power can be further reduced while searching on the manifold where the fidelity remains 1. Our method largely overcomes the problem of the convergence and is shown to be effective up to 60 ions, which suffices the need of the gate design in current trapped-ion experiments.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 11 January 2023
  • Accepted 2 March 2023

DOI:https://doi.org/10.1103/PhysRevE.107.035304

©2023 American Physical Society

Physics Subject Headings (PhySH)

Quantum Information, Science & Technology

Authors & Affiliations

Sheng-Chen Liu1, Lin Cheng1,4, Gui-Zhong Yao1,4, Ying-Xiang Wang1, and Liang-You Peng1,2,3,4,*

  • 1State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871 Beijing, China
  • 2Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
  • 3Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006 Taiyuan, China
  • 4Beijing Academy of Quantum Information Sciences, Beijing 100193, China

  • *liangyou.peng@pku.edu.cn

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 107, Iss. 3 — March 2023

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review E

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×