全光學式玻色愛因斯坦凝結實驗之建構

Abstract

本實驗完成全光式玻色–愛因斯坦凝結實驗之前期架設。實驗部 份,完成磁光阱(MOT)與光阱(ODT)之架設,我們分析並優化實驗條 件。我們以磁光阱捕捉3 × 107個原子,並降溫至40 μK。我們將磁光阱 所捕捉的冷原子團進一步載入光阱,目前已成功載入1 × 106原子,並 進行強迫蒸發致冷。優化蒸發致冷的初始條件以及效率,目前相空間 密度已達0.1,阱內剩餘原子數為2 × 104。

The goal of this experiment is to realize the rapid formation of Rubidium Bose-Einstein Condensates (BEC) in a dipole trap. We completed the experi- ment setup, including a vapor load magneto-optical trap (MOT) and a crossed dipole trap. We first analyzed and optimized the MOT parameters. We then loaded cold atoms into the crossed dipole trap. With 3×107 atoms cooled to 40 μK in the MOT, we transferred 106 atoms into the crossed dipole trap. We the proceeded with forced evaporative cooling. We optimized the evaporation trajectory, and we achieved a final phase space density of 0.1, with 2 × 104 atoms remained in the trap.