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题名	中性原子气体的自旋动力学与偏振光谱研究
作者	朱少兵
文献子类	博士
导师	王育竹
关键词	中性原子气体 neutral atomic gases 量子磁性 quantum magnetism 轨道间自旋交换 inter-orbital spin-exchange interaction 超交换 superexchange 自旋转变 spin-changing 偏振光谱 polarization spectroscopy
其他题名	Spin Dynamics and Polarization Spectroscopy with Neutral Atomic Gases
英文摘要	本论文理论研究了超冷原子光晶格系统中轨道间自旋交换对基于超交换的自旋动力学的调制效应以及高自旋费米原子光学超晶格系统中的自旋转变动力学，并实验研究了空心阴极灯中镱原子气体各同位素的偏振光谱。主要研究结果简述如下： （1）理论上研究了光晶格中超冷原子气体钟态轨道间自旋交换对超交换动力学的相干调控效应。光晶格中原子体系的量子磁性是由 Neel 序参量来表征的。通过分析局域与非局域的量子力学交换机制之间的相互影响，发现 Neel 序参量随时间的演化受到轨道间自旋交换碰撞的调制，原子的自旋动力学振荡幅度会出现周期性的塌缩与复现，其周期与亚稳态原子的填充数相关。相比半填充的情况，亚稳态原子单位填充时振幅调制周期较小。 （2）理论上研究了高自旋费米原子光学超晶格系统中的自旋转变动力学。自旋转变碰撞与隧穿之间的相互影响使得光学超晶格系统中原子的自旋动力学在不同阱深下表现为多种多样的形式。在自旋转变强度和隧穿强度数值上相当时，动力学表现为振幅受到超交换调制的自旋转变振荡。在极深和极浅的超晶格势中，动力学都表现为振荡频率只与自旋转变强度相关的简谐振荡。 （3）实验上系统研究了空心阴极灯中中性镱原子各同位素1S0-1P1跃迁的偏振光谱。通过优化圆偏振泵浦光和线偏振探测光的重叠，获得了包含若干个色散线型和一个背景包络的偏振光谱信号。通过研究偏振光谱信号对空心阴极灯放电电流、泵浦光功率、探测光功率等参量的依赖关系，获得了偏振光谱信号用于锁频的最优化参数范围。; In this thesis, the modulation of the superexchange-mediated spin dynamics via the inter-orbital spin-exchange with ultracold atoms in optical lattices and the spin dynamics with fermionic high-spin atoms in optical superlattices has been investigated theoretically. Moreover, the polarization spectroscopy of neutral ytterbium isotopes in a hollow cathode lamp has been investigated experimentally. The main results are briefly reviewed as follows: (1)The coherent control of the superexchange dynamics via the inter-orbital spin-exchange of the clock states with ultracold atomic gases in optical lattices has been investigated theoretically. The quantum magnetism of the atoms in optical lattices is characterized by the Neel order parameter. By analysing the interplay between the local and nonlocal quantum mechanical exchange mechanisms, the time evolution of the Neel order parameter is found to be modulated by the inter-orbital spin-exchange interaction. The oscillation amplitude of the spin dynamics shows periodic collapses and revivals, the periods of which depend on the filling of the metastable state atoms. The amplitude modulation period with unit-filling metastable state atoms is smaller than that of half-filling case. (2)The spin-changing dynamics with fermionic high-spin atoms in optical superlattices has been investigated theoretically. The interplay between spin-changing collisions and tunnelings results in various types of spin dynamics of the atoms in the optical superlattices with different depths. In the case that spin-changing strength and tunneling strength are comparable, the dynamics exhibit as the spin-changing oscillation with the amplitude modulated by the superexchange interaction. For the very deep and very shallow superlattice potentials, the dynamics both exhibit as simple harmonic oscillations with their oscillation frequencies both depend only on the spin-changing strength. (3)The polarization spectroscopy of 1S0-1P1 transition of neutral ytterbium isotopes in a hollow cathode lamp has been systematically studied experimentally. The polarization spectroscopy signals which comprise some dispersion profiles and an envelope are obtained by optimizing the overlap of the circularly polarized pump beam and the linearly polarized probe beam. The optimized parameters for frequency-locking applications are obtained through investigating the dependence of spectroscopy signals on the cathode lamp current, the pumping laser power and the probing laser power.
学科主题	光学
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/30970]
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	朱少兵. 中性原子气体的自旋动力学与偏振光谱研究[D].

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