Aikawa K, Frisch A, Mark M, Baier S, Grimm R, Bohn J L, Jin D S, Bruun G M, Ferlaino F
Institut für Experimentalphysik and Zentrum für Quantenphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
Institut für Experimentalphysik and Zentrum für Quantenphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria and Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria.
Phys Rev Lett. 2014 Dec 31;113(26):263201. doi: 10.1103/PhysRevLett.113.263201. Epub 2014 Dec 23.
We report on the observation of a large anisotropy in the rethermalization dynamics of an ultracold dipolar Fermi gas driven out of equilibrium. Our system consists of an ultracold sample of strongly magnetic 167Er fermions, spin polarized in the lowest Zeeman sublevel. In this system, elastic collisions arise purely from universal dipolar scattering. Based on cross-dimensional rethermalization experiments, we observe a strong anisotropy of the scattering, which manifests itself in a large angular dependence of the thermal relaxation dynamics. Our result is in good agreement with recent theoretical predictions. Furthermore, we measure the rethermalization rate as a function of temperature for different angles and find that the suppression of collisions by Pauli blocking is not influenced by the dipole orientation.
我们报告了对处于非平衡态的超冷偶极费米气体再热化动力学中一个大的各向异性的观测结果。我们的系统由处于最低塞曼子能级且自旋极化的强磁性167Er费米子的超冷样本组成。在这个系统中，弹性碰撞完全源于普遍的偶极散射。基于跨维度再热化实验，我们观测到了散射的强各向异性，这在热弛豫动力学的大角度依赖性中表现出来。我们的结果与最近的理论预测高度吻合。此外，我们测量了不同角度下再热化速率随温度的变化，发现泡利阻塞对碰撞的抑制不受偶极取向的影响。
