| 报告题目 | Using optical atomic clock to study SU(N)-symmetric interactions in Sr orbital magnetism |
| 报告人 | Dr. ZHANG Xibo |
| 报告人单位 | JILA, University of Colorado at Boulder |
| 报告时间 | 2014-09-15 |
| 报告地点 | 合肥微尺度物质科学国家实验室九楼会议室 |
| 主办单位 | 合肥微尺度物质科学国家实验室 |
| 报告介绍 | Abstract:
Inter-atomic interactions have been a key source of systematic uncertainty for the world’s best atomic clocks in the past six years. Thanks to the development of ultrastable lasers with 1×10-16 instability, these interactions are now characterized to very high precision, which not only allows our single clock ("JILA SrII") to achieve the best performance in two key ingredients necessary for a primary standard – stability and accuracy, both at the 10-18 level [1], but also enables our first-generation system ("JILA SrI") to realize a powerful laboratory to study a many-body spin system with strongly interacting, open, and driven dynamics [2]. Here we report a spectroscopic observation of SU(N £ 10) symmetry in 87Sr with I=9/2 [3] on the basis of the unprecedented measurement precision of an optical lattice clock. By encoding a pseudo-spin ½ degree of freedom in the two clock states, while keeping the system open to all 10 nuclear spin sublevels, we probe the non-equilibrium two-orbital SU(N) magnetism via Ramsey spectroscopy of atoms confined in an array of two-dimensional optical traps. We study the spin-orbital quantum dynamics and determine the relevant interaction parameters. This work lays the groundwork for using alkaline-earth atoms as test-beds for important orbital models, as well as realizing exotic quantum systems that have no counterparts in nature. [1] A New Generation of Atomic Clocks: Accuracy and Stability at the 10-18 Level. B. J. Bloom, et al. Nature 506, 71-75 (2014).
[2] A quantum many-body spin system in an optical lattice clock. M. J. Martin, et al. Science 341, 632-636 (2013).
[3] Spectroscopic observation of SU(N)-symmetric interactions in Sr orbital magnetism. X. Zhang, et al. Science, 21 August 2014 (10.1126/science.1254978). |
