Realizing multiple-qubit entangling gate in Rydberg atoms via soft quantum control

¹ International Laboratory for Quantum Functional Materials of Henan, and School of Physics and Microelectronics, Zhengzhou University - Zhengzhou 450001, China
² The Department of Control Science and Engineering, Tongji University - Shanghai 201804, China
³ Shanghai Institute of Intelligent Science and Technology, Tongji University - Shanghai 201804, China
⁴ Institute for Advanced Study, Tongji University - Shanghai, 200092, China
⁵ School of Physics and Microelectronics, Key Laboratory of Materials Physics of Ministry of Education, Zhengzhou University - Zhengzhou 450001, China
⁶ Key Laboratory for Special Functional Materials of Ministry of Education, and School of Materials and Engineering, Henan University - Kaifeng 475001, China

^(a) E-mail: mengruYun@163.com (corresponding author)
^(b) E-mail: shuming_cheng@tongji.edu.cn
^(c) E-mail: llyan@zzu.edu.cn
^(d) E-mail: jiayu@zzu.edu.cn

Received: 11 March 2022
Accepted: 28 November 2022

Abstract

Entangling gates are important for the generation of entanglement in quantum communicational and computational tasks. In this work, we propose an efficient protocol to realize the multi-qubit entangling gates with high fidelity in Rydberg atoms. Particularly, we apply the technique of soft quantum control to design the off-resonant pulses such that the atoms are driven to the ground-state subspace via unconventional Rydberg pumping. Thus, our scheme is insensitive to the decay effect as all atoms are only virtually excited. Moreover, Gaussian temporal modulation is further adopted to improve its robustness against the model uncertainty, such as operating time and environment noise. Finally, we perform numerical simulation to validate the effectiveness of our scheme. Hence, our work has potential applications in quantum information processing based on Rydberg atoms.