title: Anisotropic Expansion of a Thermal Dipolar Bose Gas.
abstract: 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.
authors: Department of Physics, Stanford University, Stanford, California 94305, USA.|E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
authors: Y
authors: Y
authors: Tang
authors: LPTMS, CNRS, University Paris Sud, Université Paris-Saclay, 91405 Orsay, France.
authors: A G
authors: AG
authors: Sykes
authors: E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.|Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors: N Q
authors: NQ
authors: Burdick
authors: E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.|Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors: J M
authors: JM
authors: DiSciacca
authors: LPTMS, CNRS, University Paris Sud, Université Paris-Saclay, 91405 Orsay, France.
authors: D S
authors: DS
authors: Petrov
authors: Department of Physics, Stanford University, Stanford, California 94305, USA.|E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.|Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors: B L
authors: BL
authors: Lev