我們完成了一個混合銣原子與鉀原子的磁光陷阱 (Magneto-Optical Trap: MOT)。實驗所用的雷射系統，真空系統，磁光陷阱以及成像系統在論文中皆有詳細的描述。此混合磁光陷阱中可捕捉到10^8個銣原子(87Rb)及10^9個鉀原子(39K)。觀察磁光陷阱中原子數量的成長過程，可以看到異核原子間的超冷碰撞所造成原子數量上的損失。藉由了解銣原子與鉀原子間的超冷碰撞(Ultracold collision loss)及交互作用，可進一步探討形成超冷極性分子（Ultracold dipolar molecule）的可能。

We perform a double-species magneto-optical trap of 87Rb and 39K. The experiment apparatus of lasers, vacuum system, MOT and imaging system is described. Typically
the atom numbers are 1×108 for 87Rb and 1×109 for 39K in double MOT operation.
Cross-species cold collision loss was observed. The heteronuclear cold collision loss
rate is determined by loading one species MOT with the presence and absence of
the other species MOT. The cross-species MOT is a suitable source to form the cold
mixture.

[1] M. A. Baranov, M. S. Mar’enko, V. S. Rychkov, and G. V. Shlyapnikov, Phys.
Rev. A 66, 013606 (2002).
[2] M. R. Tarbutt et al., Physical Review Letters 92, 173002 (2004).
[3] J. Doyle, B. Friedrich, R. V. Krems, and F. Masnou-Seeuws, EUR.PHYS.J.D 31,
149 (2004).
[4] D. Wang et al., Physical Review Letters 93, 243005 (2004).
[5] C. A. R. Markus Greiner and D. S. Jin, Nature 426, 537 (2003).
[6] R. V. Krems et al., Phys. Rev. A 66, 030702 (2002).
[7] J. van Veldhoven et al., European Physical Journal D 31, 337 (2004).
[8] E. L. Raab et al., Phys. Rev. Lett. 59, 2631 (1987).
[9] C. Cohen-Tannoudji, physrep 219, 153 (1992).
[10] K. Gibble, S. Kasapi, and S. Chu, Optics Letters 17, 526 (1992).
[11] K. Lindquist, M. Stephens, and C. Wieman, Phys. Rev. A 46, 4082 (1992).
[12] T. Walker, D. Sesko, and C. Wieman, Phys. Rev. Lett. 64, 408 (1990).
[13] M. W. Mancini et al., European Physical Journal D 30, 105 (2004).