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题名	基于原子芯片的原子输运研究
作者	赵子豪
文献子类	硕士
导师	李晓林
关键词	原子输运 Atom transport 双阱 Double well 原子芯片 Atom chip 直接蒙特卡罗模拟 Direct simulation Monte-Carlo
其他题名	Atom transport on atom chips
英文摘要	满足宇称-时间对称（Parity-Time Symmetry，简称 PT 对称）的量子系统即使 不满足厄米性，也可以得到全实数的本征能谱。关于 PT 对称的研究已由非厄密 量子力学扩展到光学、电子电路和超颖材料等诸多领域，许多奇特的物理效应在 相关的实验中被发现。观测量子系统中的 PT 对称破缺要求超冷原子具有相互耦 合的两内态以及可控的原子布居损耗或增益。论文提出了通过原子输运获得受控 原子增益的方法，并研究了原子芯片上的原子输运过程。 首先，论文利用原子芯片磁阱可以灵活设计的优势，建立了用于原子输运的 双阱模型。通过控制双阱的形状变化，实现了输运至目标区域中的原子在特定时 间内呈指数型增长。 然后，论文利用直接蒙特卡洛（Direct Simulation Monte-Carlo，简称 DSMC） 方法模拟了原子输运过程，研究了初始装载的原子数 0 N 、原子云的初始温度 0 T 和抬升势阱所用时间 t ? 三种因素分别对原子增益速率的影响。计算发现：原子 增益速率随原子云的初始温度的升高而减小；在 2ms t ?≥ 时，原子增益速率随抬 升左侧势阱所用时间减少而增大；原子输运效率随初始装载的原子数增多而升高。 最后，论文介绍了原子芯片系统的实验工作。设计了原子芯片系统的磁屏蔽 并对屏蔽效果进行了仿真。设计并测试了玻色-爱因斯坦凝聚（Bose-Einstein condensates，简称 BEC）实验系统中原子推送光的光路。调节了参考腔使其与稳 频激光器耦合并测量了其精细度。对铷原子吸收池制作了加热温控系统。 本论文的创新点在于提出了基于原子芯片的动态控制双磁阱中原子输运过 程的方法，实现特定时间内原子布居的指数增长且增益速率可调控，论文所取得 的成果将为今后设计用于研究铷原子PT对称的原子芯片实验和观测量子系统中 PT 对称破缺机制及相关物理效应提供理论支持。; The quantum system with parity-time symmetry (PT symmetry) can also have a full real eigen energy spectrum even if it’s non-Hermitian. The study of PT symmetry has been extended from non-Hermitian quantum mechanics to many fields like optics, electronic circuits, metamaterials et al, and many peculiar physical effects are found in the relevant experiments. To observe PT-symmetry-breaking in a quantum system, it is required that ultracold atoms have two coupled internal states and controllable atom population loss or gain. The thesis proposes a method to obtain atom population gain by atom transport and studies the atom transport process. Firstly, the thesis builds a double-well model for atom transport by taking the advantage of that the shape of the magnetic traps on atom chip can be designed flexibly. By controlling the double well potential’s shape, the number of atoms transported to the target area has an exponential growth within a specific time frame. Next, the thesis uses Direct Simulation Monte-Carlo (DSMC) method to simulate the atom transport process. The effects of the three factors, including the initial atom number 0 N in the trap, the initial temperature 0 T of the atom cloud and the rising time t? of the left sub-well on the rate of atom gain, are studied. The calculation indicates that, with the initial temperature of the atom cloud increased, the atom gain rate becomes smaller; when 2ms t ?≥ , the atom gain rate becomes larger with the reduced rising time of the left sub-well; and the atom transport efficiency increases as the initial atom number in the trap becomes larger. Finally, the thesis introduces the experiments work of the atom chip system. The magnetic shielding of the atom-chip system is designed and the shielding effectiveness is simulated. The optical paths of the push light in the Bose-Einstein condensation (BEC) experiment system is designed and tested. The reference cavity is adjusted to couple with the frequency stabilized laser and the finess is measured. The heating temperature control system for the rubidium atoms cell is designed. The innovation of this thesis is a proposal of a method to dynamically control the atom transport in the magnetic double well potential generated by the atom chip, with exponential growth of atom number and adjustable gain rate for a particular period of time. The achievements presented in the thesis will provide theoretical supports for the atom chip experiments of PT symmetry of rubidium atoms, as well as observing the PT symmetry-breaking and the relevant physical effects in quantum systems.
学科主题	光学工程
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/31126]
专题	中国科学院上海光学精密机械研究所
作者单位	中国科学院上海光学精密机械研究所
推荐引用方式 GB/T 7714	赵子豪. 基于原子芯片的原子输运研究[D].

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