Tang Y, Sykes A G, Burdick N Q, DiSciacca J M, Petrov D S, Lev B L
Department of Physics, Stanford University, Stanford, California 94305, USA.
E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
Phys Rev Lett. 2016 Oct 7;117(15):155301. doi: 10.1103/PhysRevLett.117.155301. Epub 2016 Oct 4.
We report on the anisotropic expansion of ultracold bosonic dysprosium gases at temperatures above quantum degeneracy and develop a quantitative theory to describe this behavior. The theory expresses the postexpansion aspect ratio in terms of temperature and microscopic collisional properties by incorporating Hartree-Fock mean-field interactions, hydrodynamic effects, and Bose-enhancement factors. Our results extend the utility of expansion imaging by providing accurate thermometry for dipolar thermal Bose gases. Furthermore, we present a simple method to determine scattering lengths in dipolar gases, including near a Feshbach resonance, through observation of thermal gas expansion.
我们报道了处于量子简并温度以上的超冷玻色钬气体的各向异性膨胀，并发展了一种定量理论来描述这种行为。该理论通过纳入哈特里-福克平均场相互作用、流体动力学效应和玻色增强因子，以温度和微观碰撞特性来表达膨胀后的纵横比。我们的结果通过为偶极热玻色气体提供精确的温度测量，扩展了膨胀成像的效用。此外，我们提出了一种简单的方法，通过观察热气体膨胀来确定偶极气体中的散射长度，包括在费什巴赫共振附近。
