发表机构
Pohang University of Science and Technology (POSTECH)（浦项科技大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过冷原子碰撞器实验，观测到强耦合超声速杂质在玻色凝聚体中的极化子响应，表现为共振附近动力学惯性的显著增强。
AI 中文摘要
可移动杂质如何与多体环境交换动量和能量，是非平衡量子物理中的一个核心问题。当杂质快速运动并与其环境强耦合时，这种交换变得尤为复杂。在此，我们实现了一个相互作用可调的冷原子碰撞器，其中费米子$^{40}$K杂质浸没在$^{23}$Na玻色-爱因斯坦凝聚体中。一种物种选择性拉曼脉冲同时启动凝聚体并淬灭种间散射长度，产生初始相对速度，为凝聚体声速的36倍。我们追踪随后的相对运动，同时将种间相互作用从弱耦合调至共振。在弱和中等耦合下，杂质动力学可由有限能量两体碰撞模型很好地描述。然而，在共振附近，早期杂质加速度相对于两体预测显著抑制，对应于表观动力学惯性的强烈增强。这种增强在两个不同的费什巴赫共振附近被观察到。这些观测为简并玻色-费米混合物在强耦合、超声速区域中的极化子响应提供了证据。
英文摘要
How a mobile impurity exchanges momentum and energy with a many-body environment is a central question in nonequilibrium quantum physics. This exchange becomes particularly complex when the impurity moves rapidly and is strongly coupled to its bath. Here, we realize an interaction-tunable cold-atom collider with fermionic $^{40}$K impurities immersed in a $^{23}$Na Bose--Einstein condensate. A species-selective Raman pulse simultaneously launches the condensate and quenches the interspecies scattering length, producing an initial relative speed 36 times the condensate speed of sound. We track the ensuing relative motion as the interspecies interaction is tuned from weak coupling to resonance. At weak and intermediate coupling, the impurity dynamics are well described by a finite-energy two-body collision model. Near resonance, however, the early-time impurity acceleration is markedly suppressed relative to the two-body prediction, corresponding to a strong enhancement of the apparent dynamical inertia. The enhancement is observed near two distinct Feshbach resonances. These observations provide evidence for a polaronic response in the strongly coupled, supersonic regime of a degenerate Bose--Fermi mixture.
Comments6+5 pages, 4+4 figures
