基于共振里德伯偶极-偶极相互作用的双反阻塞机制及量子逻辑门的实现  

Implementation of the Rydberg double anti-blockade regime and the quantum logic gate based on resonant dipole-dipole interactions

作　　者：金钊 李芮 公卫江[1] 祁阳 张寿[3] 苏石磊 Jin Zhao;Li Rui;Gong Wei-Jiang;Qi Yang;Zhang Shou;Su Shi-Lei(Department of Physics,College of Sciences,Northeastern University,Shenyang 110819,China;State Key Laboratory of Rolling and Automation,School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Department of Physics,College of Science,Yanbian University,Yanji 133002,China;School of Physics and Microelectronics,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]东北大学理学院物理系,沈阳110819 [2]东北大学材料科学与工程学院,轧制技术与连轧自动化国家重点实验室,沈阳110819 [3]延边大学理学院物理系,延吉133002 [4]郑州大学物理工程学院,郑州450001

出　　处：《物理学报》2021年第13期80-88,共9页Acta Physica Sinica

基　　金：国家自然科学基金青年科学基金(批准号:11804308);中国博士后科学基金(批准号:2018T110735);中央高校基本科研业务费专项资金(批准号:N2005008);东北大学博士后基金(批准号:20200322)资助的课题.

摘　　要：里德伯原子由于具有较长的能级寿命和易于操控的特点已成为卓越的信息载体之一.近年来,关于里德伯原子性质的研究得到逐步的发展和完善,特别是基于里德伯原子间范德瓦耳斯力诱导的单能级里德伯阻塞和反阻塞效应.然而,随着原子间距离的改变,里德伯相互作用将导致更加复杂的动力学行为.本文主要研究在原子间距小于其特征长度的情况下,如何根据构建的里德伯反阻塞及双反阻塞机制一步实现两量子比特控制相位门和交换门,在此范围内的原子间相互作用将涉及多个能级的布居交换.数值模拟表明:里德伯阻塞与双反阻塞机制的解析和数值结果能够达到高度一致,理想情况下控制相位门和交换门的平均保真度分别为99.35%和99.67%,此结果对于抵抗高激发里德伯态的自发辐射具有一定的鲁棒性.希望本文的研究能够为里德伯原子系统中实现大规模容错量子计算提供必要的理论支持与实验依据.Quantum information science is an emerging field that applies the quantum coherence and correlation to cause the revolutionary advances in computation,communication,and fundamental quantum science.As an irreducible ingredient,Rydberg quantum gate is considered to be a powerful resource with great promises to a wide range of quantum information tasks far beyond the original gate proposals,since the remarkable features characterized by Rydberg atom are long lifetime and giant polarizability.In recent years,the research mainly focused on the properties of Rydberg atom,especially for the case where the effects of Rydberg blockade and antiblockade involving single level for each atom are dominated by van der Waals forces.However,with the variation of interatomic distance,Rydberg interactions can induce more complicated dynamical behavior.This paper studies the implementation of controlled-phase gate and swap gate in one step based on the constructed Rydberg antiblockade(RAB)and double antiblockade(RDAB)regimes when the interatomic distance is less than the characteristic length.Different from the conventional RAB regime that requires weak Rydberg-Rydberg interaction(RRI),our attainable strategy is to compensate the RRI-induced energy shift by properly tuning the detuning between the driving field and atomic transition frequencies.In addition,the proposed RDAB mechanism is a new physical insight that can enable two pairs of Rydberg states belonging to different atoms to be excited,simultaneously.In contrast to other blocking schemes or the schemes without requirements for strong interactions,the merits of our proposal lies in the strong dipole-dipole interaction between two atoms,leading to the population exchange of multiple energy levels.Numerical simulations show that the time evolution of the population for collective double-atom basis obtained from the original Hamiltonian agrees well with the analytical results given by the effective Hamiltonian.In the ideal case,the average fidelity of the controlled-phase(swap)

关 键 词：里德伯原子 反阻塞机制 量子逻辑门 偶极-偶极相互作用 

分 类 号：O562[理学—原子与分子物理] O413[理学—物理]