Protected two-qubit entangling gate with mechanical driven continuous dynamical decoupling  

作　　者：Xue-Jian Sun Wen-Xiao Liu Hao Chen Cheng-Yuan Wang Hui-Zhong Ma Hong-Rong Li 

机构地区：[1]College of Physics and Telecommunication Engineering,Zhoukou Normal University,Zhoukou 466001,China [2]Department of Physics and Electronics,North China University of Water Resources and Electric Power,Zhengzhou 450046,China [3]College of Physics and Electronic Information Engineering,Qinghai Normal University,Xining 810008,China [4]Institute of Quantum Optics and Quantum Information,School of Physics,Xi'an Jiaotong University,Xi'an 710049,China

出　　处：《Communications in Theoretical Physics》2022年第6期21-30,共10页理论物理通讯（英文版）

基　　金：supported by the Natural Science Foundation of Henan Province (No. 222300420233)。

摘　　要：In this work, we propose a high-fidelity phonon-mediated entangling gate in a hybrid mechanical system based on two silicon-vacancy color centers in diamond. In order to suppress the influence of the spin decoherence on the entangling gate, we use a continuous dynamical decoupling approach to create new dressed spin states, which are less sensitive to environmental fluctuations and exhibit an extended T_(2)^(*) spin dephasing time. The effective spin-spin Hamiltonian modified by the mechanical driving field and the corresponding master equation are derived in the dispersive regime. We show that in the presence of the mechanical driving field, the effective spin-spin coupling can be highly controlled. By calculating the entangling gate fidelity in the dressed basis, we find that once the mechanical field is turned on, the gate fidelity can be significantly improved. In particular, under an optimized spin-phonon detuning and a stronger Rabi frequency of the mechanical driving field, the two-qubit gate is capable of reaching fidelity exceeding 0.99. Moreover, by employing appropriate driving modulation, we show that a highfidelity full quantum gate can be also realized, in which the initial and final spin states are on a bare basis. Our work provides a promising scheme for realizing high-fidelity quantum information processing.

关 键 词：silicon-vacancy color centers high-fidelity entangling gate mechanical driving modulation quantum information processing 

分 类 号：O413[理学—理论物理]