标题： 相互作用的玻色气体如何散射光 显示英文标题

标题： How interacting Bose gases scatter light

摘要： 量子统计的基本表现之一是相同玻色子固有的聚集倾向，这在Hanbury Brown-Twiss效应和玻色-爱因斯坦凝聚中可见。如果原子散射到已占据的量子态中，这种倾向可以增强基本过程的速率，例如原子-原子和原子-光散射。对于非相互作用的玻色子，光散射的增强简单地由玻色子刺激因子$1 + N_{\rm f}$给出，其中$N_{\rm f}$是原子最终动量态的占据数。在这里，我们研究了非共振光与准均匀玻色气体中原子的散射，并表明即使弱相互作用，不会显著改变动量分布，也会对原子-光散射产生显著影响。由于（空间局部）超越平均场的原子关联，弱排斥相互作用可以完全抑制散射的玻色增强，而吸引力则会增加散射速率。此外，如果相互作用迅速调节，光散射揭示了比动量空间种群动力学快几个数量级的相关动力学。其对动态超越平均场效应的高度敏感性使得非共振光散射成为研究超冷原子气体中多体物理的简单而有力的探测工具。 显示英文摘要

摘要： The innate tendency of identical bosons to bunch, seen in the Hanbury Brown-Twiss effect and Bose-Einstein condensation, is a primary manifestation of quantum statistics. This tendency can enhance the rates of fundamental processes such as atom-atom and atom-light scattering if the atoms scatter into already occupied quantum states. For non-interacting bosons, the enhancement of light scattering is simply given by the bosonic-stimulation factor $1 + N_{\rm f}$, where $N_{\rm f}$ is the occupation of the atom's final momentum state. Here, we study scattering between off-resonant light and atoms in a quasi-homogeneous Bose gas with tunable interactions and show that even weak interactions, which do not significantly alter the momentum distribution, have a dramatic effect on the atom-light scattering. Due to (spatially local) beyond-mean-field atomic correlations, weak repulsive interactions can completely suppress the bosonic enhancement of scattering, while attractive ones increase the scattering rate. Moreover, if the interactions are rapidly tuned, light scattering reveals correlation dynamics that are orders of magnitude faster than the momentum-space population dynamics. Its extreme sensitivity to dynamical beyond-mean-field effects makes off-resonant light scattering a simple and powerful probe of many-body physics in ultracold atomic gases.