Tobias William G, Matsuda Kyle, Valtolina Giacomo, De Marco Luigi, Li Jun-Ru, Ye Jun
JILA, National Institute of Standards and Technology and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.
Phys Rev Lett. 2020 Jan 24;124(3):033401. doi: 10.1103/PhysRevLett.124.033401.
We observe thermalization in the production of a degenerate Fermi gas of polar ^{40}K^{87}Rb molecules. By measuring the atom-dimer elastic scattering cross section near the Feshbach resonance, we show that Feshbach molecules rapidly reach thermal equilibrium with both parent atomic species. Equilibrium is essentially maintained through coherent transfer to the ground state. Sub-Poissonian density fluctuations in Feshbach and ground-state molecules are measured, giving an independent characterization of degeneracy and directly probing the molecular Fermi-Dirac distribution.
我们在极化的(^{40}K^{87}Rb)分子简并费米气体的产生过程中观察到了热化现象。通过测量费什巴赫共振附近的原子 - 二聚体弹性散射截面，我们表明费什巴赫分子能迅速与两种母体原子物种达到热平衡。平衡主要通过向基态的相干转移得以维持。我们测量了费什巴赫分子和基态分子中的亚泊松密度涨落，给出了简并的独立表征，并直接探测了分子费米 - 狄拉克分布。
