Esteve J, Trebbia J-B, Schumm T, Aspect A, Westbrook C I, Bouchoule I
Laboratoire Charles Fabry, CNRS et Université Paris Sud 11, 91403 Orsay Cedex, France.
Phys Rev Lett. 2006 Apr 7;96(13):130403. doi: 10.1103/PhysRevLett.96.130403. Epub 2006 Apr 6.
We report in situ measurements of density fluctuations in a quasi-one-dimensional 87Rb Bose gas at thermal equilibrium in an elongated harmonic trap. We observe an excess of fluctuations compared to the shot-noise level expected for uncorrelated atoms. At low atomic density, the measured excess is in good agreement with the expected "bunching" for an ideal Bose gas. At high density, the measured fluctuations are strongly reduced compared to the ideal gas case. We attribute this reduction to repulsive interatomic interactions. The data are compared with a calculation for an interacting Bose gas in the quasicondensate regime.
我们报告了在一个细长谐波势阱中处于热平衡的准一维87Rb玻色气体中密度涨落的原位测量结果。与不相关原子预期的散粒噪声水平相比，我们观察到涨落过剩。在低原子密度下，测量到的过剩与理想玻色气体预期的“聚束”现象吻合良好。在高密度下，与理想气体情况相比，测量到的涨落大幅降低。我们将这种降低归因于原子间的排斥相互作用。我们将数据与准凝聚态 regime 中相互作用玻色气体的计算结果进行了比较。
