超冷~6Li费米原子窄Feshbaeh共振的研究

发布时间：2018-04-19 22:27

本文选题：窄Feshbach共振 + 超冷费米气体　；参考：《华东师范大学》2017年硕士论文

【摘要】：随着激光冷却技术的发展,超冷费米气体已逐渐成为当前原子分子物理学的研究热点。光学诱导和磁场可控的Feshbach共振技术可以精确调控原子间的相互作用,广泛用于研究分子的玻色-爱因斯坦凝聚和费米原子的BCS共振超流。本论文研制了一套大磁场强度、可快速变化的精密磁场控制系统,该系统可以实现1200高斯的微秒量级快速稳定控制,磁场稳定度优于10毫高斯。利用这套精密的磁场控制系统,通过对6Li费米气体采用塞曼减速、磁光阱冷却、偶极阱俘获和蒸发冷却等冷却方法实现了 6Li原子气体的量子简并和6Li2分子的玻色爱因斯坦凝聚。本论文还观测了 6Li原子最低能态的窄Feshbach共振,发现其共振点在543.278 G附近,与理论计算结果相一致,为将来研究窄Feshbach共振强相互作用提供重要的依据。同时证实了窄Feshbach共振区域原子间相互作用强度的能量依靠关系,研究了窄Feshbach共振区域的RF跃迁频率偏移现象,对Feshbach共振磁场的研制以及6Li窄Feshbach共振的进一步研究有一定的指导意义。
[Abstract]:With the development of laser cooling technology, supercooled Fermi gas has gradually become a hot spot in atomic and molecular physics. The optically induced and magnetic field controllable Feshbach resonance technique can accurately regulate the interaction between atoms. It is widely used to study the Bose-Einstein condensation of molecules and the BCS resonance supercurrent of Fermi atoms. In this paper, a set of precision magnetic field control system with large magnetic field intensity and rapid variation has been developed. The system can realize 1200 Gao Si's microsecond order of rapid and stable control, and the magnetic field stability is better than 10 mm Gao Si. Using this precise magnetic field control system, the 6Li Fermi gas is cooled by Zeeman deceleration and magneto-optic trap cooling. The quantum degeneracy of 6Li atom gas and the Bose-Einstein condensation of 6Li2 molecule are realized by dipole trap capture and evaporative cooling. In this paper, the narrow Feshbach resonance of the lowest energy state of the 6Li atom is observed. It is found that the resonance point is near 543.278 G, which is consistent with the theoretical results, which provides an important basis for the study of the strong interaction of the narrow Feshbach resonance in the future. At the same time, the energy dependence relation of the intensity of the interaction between atoms in the narrow Feshbach resonance region is confirmed, and the phenomenon of RF transition frequency migration in the narrow Feshbach resonance region is studied. It has certain guiding significance for the development of Feshbach resonance magnetic field and the further study of 6Li narrow Feshbach resonance.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O562

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