论文标题
Bose-Einstein冷凝物和正交性灾难中的移动杂质
Mobile impurity in a Bose-Einstein condensate and the orthogonality catastrophe
论文作者
论文摘要
我们分析了稀释的Bose-Einstein冷凝物（BEC）中杂质的特性。首先，在理想BEC中，静态杂质的准粒子残基被证明会随着颗粒数的增加而消失，作为拉伸指数，导致了骨骨正交性灾难。然后，我们引入了一个变异的ANSATZ，该杂物恢复了这一确切的结果，并描述了杂质的宏观敷料，包括其背部动作到BEC上以及Bogoliubov近似之外的Boson-Boson-Boson排斥力。这一ANSATZ预测，每当BEC成为理想的情况下，移动杂质也会发生正交性灾难。最后，我们表明我们的安萨兹与实验结果非常吻合。
We analyze the properties of an impurity in a dilute Bose-Einstein condensate (BEC). First the quasiparticle residue of a static impurity in an ideal BEC is shown to vanish with increasing particle number as a stretched exponential, leading to a bosonic orthogonality catastrophe. Then we introduce a variational ansatz, which recovers this exact result and describes the macroscopic dressing of the impurity including its back-action onto the BEC as well as boson-boson repulsion beyond the Bogoliubov approximation. This ansatz predicts that the orthogonality catastrophe also occurs for mobile impurities, whenever the BEC becomes ideal. Finally, we show that our ansatz agrees well with experimental results.
