论文标题
位置和动量空间的两体相关性
Position- and momentum-space two-body correlations in a weakly interacting trapped condensate
论文作者
论文摘要
我们研究了在低温下弱相互作用的，谐波的原子 - 玻色子 - 阳离子 - 原子 - 玻色子 - 内斯坦在低温下凝结气体的位置和动量空间的两体相关性。两体相关性是在Bogoliubov近似中计算出来的，与空间均匀的情况相比，捕获气体的特征性突出显示。在位置空间中，我们恢复了由排斥的原子间相互作用在陷阱中心周围和外部热云中的束中诱导的抗束束。在动量空间中，束签名出现在动量的相等或相反的值中，并显示出奇特的特征作为动量和温度的函数。与光学汉伯里棕色和Twiss效应相比，近距离的束信号的幅度是由物质场状态的混乱性质固定的，其线宽被证明是由相关陷阱内动量成分的有限空间大小的（倒数）设置的。相反，相对摩梅塔处的束信号的线宽仅取决于冷凝水大小。
We investigate the position- and momentum-space two--body correlations in a weakly interacting, harmonically trapped atomic Bose-Einstein condensed gas at low temperatures. The two-body correlations are computed within the Bogoliubov approximation and the peculiarities of the trapped gas are highlighted in contrast to the spatially homogeneous case. In the position space, we recover the anti-bunching induced by the repulsive inter-atomic interaction in the condensed fraction localized around the trap center and the bunching in the outer thermal cloud. In the momentum space, bunching signatures appear for either equal or opposite values of the momentum and display peculiar features as a function of the momentum and the temperature. In analogy to the optical Hanbury Brown and Twiss effect, the amplitude of the bunching signal at close-by momenta is fixed by the chaotic nature of the matter field state and its linewidth is shown to be set by the (inverse of the) finite spatial size of the associated in-trap momentum components. In contrast, the linewidth of the bunching signal at opposite-momenta is only determined by the condensate size.
