基于周期极化KTiOPO4晶体的高亮度纠缠源研制  

Design of high brightness entangled source based on periodically poled KTiOPO_4 crystal

作　　者：任继刚[1,2] 张涵[2] 蔡昕东[2] 印娟[2] 周飞[1] 彭承志[1,2] 

机构地区：[1]清华大学物理系,北京100084 [2]中国科学技术大学近代物理系,合肥微尺度物质科学国家实验室,合肥230026

出　　处：《物理学报》2009年第8期5169-5173,共5页Acta Physica Sinica

基　　金：清华985基金(批准号:051110001);国家自然科学基金(批准号:60708023)资助的课题~~

摘　　要：量子纠缠是量子信息领域的核心资源,目前利用β型硼酸钡(BBO)晶体参量下转换制备的纠缠光子对的亮度较低,它直接制约了量子通信的最远距离,已无法满足星地实用化量子通信的发展需求.利用周期极化KTiOPO4晶体,采用准相位匹配技术设计产生了一种后选择的纠缠源,测得的符合计数达到了16×103s-1mW-1,极化对比度达到27:1,在亮度上比基于BBO的量子纠缠光源提高了一个数量级以上.这一高亮度的纠缠源可以广泛应用于量子密钥分发、量子隐形传态以及量子计算等新兴量子信息领域,为实现全球化量子通信提供了有力的保障.Entangled states are key resource for quantum information processing. In linear optics quantum computing, the most widely used entanglement resource is polarization entangled photon pairs generated via type- Ⅱspontaneous parametric down-conversion. However, the brightness is not sufficient to perform quantum communication experiment between ground and satellite. In this paper we have developed a high-brightness entangled resource based on periodic polarization and quasi-phase marched periodically poled KTiOPO4 crystal. The number of generated entangled pairs is about 1.6 ×10^3smW^-1 and the visibility is 27 ： 1. Our source is with about one order of magnitude brighter than previous sources based on E-barium borate crystal. This leads to an immediate possibility for applications in the field of quantum key distribution, quantum teleportation and quantum computation. Particularly it would form a sohd basis for future global quantum network.

关 键 词：纠缠态 准相位匹配 周期极化KTiOPO4晶体 

分 类 号：O413.1[理学—理论物理]