离子阱中以声子为媒介的多体量子纠缠与逻辑门  

Phonon-mediated many-body quantum entanglement and logic gates in ion traps

作　　者：刘腾 陆鹏飞 胡碧莹 吴昊 劳祺峰 边纪 刘泱 朱峰 罗乐 Liu Teng;Lu Peng-Fei;Hu Bi-Ying;Wu Hao;Lao Qi-Feng;Bian Ji;Liu Yang;Zhu Feng;Luo Le(School of Physics and Astronomy,Sun Yat-Sen University,Zhuhai 519082,China;Center of Quantum Information Technology,Shenzhen Research Institute,Sun Yat-Sen University,Shenzhen 518087,China;State Key Laboratory of Optoelectronic Materials and Technologies,Sun Yat-Sen University,Guangzhou 510275,China)

机构地区：[1]中山大学物理与天文学院,珠海519082 [2]中山大学深圳研究院,量子信息技术中心,深圳518087 [3]中山大学,光电材料与技术国家重点实验室,广州510275

出　　处：《物理学报》2022年第8期11-25,共15页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11774436,11974434,12074439);广东省自然科学基金(批准号:2020A1515011159);广东省重点领域研发计划项目(批准号:2019B030330001);广州市科技计划项目(批准号:202102080380);中山大学中央高校基本科研业务费专项资金(批准号:2021qntd28);中国博士后科学基金(批准号:2021M703768);广东省珠江人才计划项目(批准号:2017GC010656);中央引导地方科技发展资金(批准号:2021Szvup172)资助的课题。

摘　　要：高保真度的多离子纠缠和量子逻辑门是离子阱量子计算的基础.在现有的方案中,M?lmer-S?rensen门是比较成熟的实现多离子纠缠和量子逻辑门的实验方案.近年来,还出现了通过设计超快激光脉冲序列,在Lamb-Dicke区域以外实现超快量子纠缠和量子逻辑门的方案.这些方案均借助离子链这一多体量子系统的声子能级来耦合离子之间的自旋状态,并且均通过调制激光脉冲或设计合适的脉冲序列解耦多运动模式,来提高纠缠门的保真度.本文从理论和实验层面分析了这些多体量子纠缠和量子逻辑门操作的关键技术,揭示了离子阱中利用激光场驱动离子链运动态,通过非平衡过程中的非线性相互作用,来实现量子逻辑门的基本物理过程.The high-fidelity multi-ion entangled states and quantum gates are the basis for trapped-ion quantum computing.Among the developed quantum gate schemes,M?lmer-S?rensen gate is a relatively mature experimental technique to realize multi-ion entanglement and quantum logic gates.In recent years,there have also been schemes to realize ultrafast quantum entanglement and quantum logic gates that operate outside the Lamb-Dicke regime by designing ultrafast laser pulse sequences.In such a many-body quantum system,these entanglement gates couple the spin states between ions by driving either the phonon energy level or the motional state of the ion chain.To improve the fidelity of quantum gates,the modulated laser pulses or the appropriately designed pulse sequences are applied to decouple the multi-mode motional states.In this review,we summarize and analyze the essential aspects of realizing these entanglement gates from both theoretical and experimental points of view.We also reveal that the basic physical process of realizing quantum gates is to utilize nonlinear interactions in non-equilibrium processes through driving the motional states of an ion chain with laser fields.

关 键 词：离子阱量子计算 量子逻辑门 量子纠缠 自旋依赖相互作用 

分 类 号：O413[理学—理论物理]