基于阿基米德螺线的三导线环形磁导引  

Three wires ring magnetic guide based on Archimedean spirals

作　　者：凌云龙 汪川 张海潮[1] Ling Yun-Long;Wang Chuan;Zhang Hai-Chao(Key Laboratory for Quantum Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海光学精密机械研究所,量子光学重点实验室,上海201800 [2]中国科学院大学,北京100049

出　　处：《物理学报》2020年第10期9-17,共9页Acta Physica Sinica

基　　金：基础科研科学挑战专题(批准号:TZ2018003-3)资助的课题.

摘　　要：提出了一种三线阿基米德螺线结构产生环形磁势阱以囚禁中性原子的导引方案.该结构具有π/3旋转对称性,由三根导线组成.每根导线包含一对由圆弧连接的阿基米德螺线,且具有中心对称性.这种结构能够避免电流引线端导致的导引缺口问题.当加载直流电时,可以形成闭合的环形磁导引,但导引中心存在磁场零点.利用时间轨道平均势原理,在直流电的基础上再加载交流调制,对调制电流的参数进行分析和讨论后给出优化方案,使环形磁导引中心无磁场零点,同时平滑了环形磁导引中心磁场强度在角向上的起伏变化.该结构可以刻蚀在芯片表面,具有生产工艺简单、调制稳定等优点,有利于实现导引型原子芯片陀螺仪.We propose a scheme to create a ring magnetic guide based on Archimedean spirals.This scheme is significant to obtaining large circle area for atom interference and the realization of guided atom-interferometer gyroscopes.Then the scheme can be used to realize an inertial sensing system which is independent of the GPS system.The wires structure with π/3 rotational symmetry is composed of three wires.Each wire is centrosymmetric and consists of a pair of Archimedean spirals connected by two arcs.Consequently,the leading wire ends of the layout can be arranged separately in the different place of the layout plane.If the leading wire ends are put together somewhere,the closed ring guide cannot form and a gap appears in the guide due to the concentrated distribution of the leading wire ends.Since the leading wire ends distribute in the different location with π/3 rotational symmetry in our scheme,when direct currents are applied,the closed ring trap can be generated ingeniously.We calculate and analyze the magnetic field distribution generated by our structure after loading currents in the cylindrical coordinates system.To get higher sensitivity compared to GPS and make the ring trap locate in a proper height above the chip surface,we set the initial radius of Archimedean spirals a=5 mm and the distance between neighboring spirals d=0.1 mm.When three wires carry direct currents in an opposite currentphase-difference between the adjacent wires,a closed ring magnetic guide indeed appears but with six zero magnetic field points along the guide center.Because of the variation of the current density along r direction in Archimedean spirals,the magnetic field of the guide center is not zero at most angle.However,the variation cannot avoid the existence of zero points and the distribution of the zero points is determined by the rotational symmetry of the wires structure.Since atoms near the zero points of the magnetic field would be lost from the trap,the zero points must be removed from the center of the ring guide.Based

关 键 词：环形磁导引 阿基米德螺线 原子芯片 交流调制 

分 类 号：O441.2[理学—电磁学]