Universal Scaling Laws in the Dynamics of a Homogeneous Unitary Bose Gas.

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Glidden, Jake AP 
Lopes, Raphael 
Navon, Nir 

We study the dynamics of an initially degenerate homogeneous Bose gas after an interaction quench to the unitary regime at a magnetic Feshbach resonance. As the cloud decays and heats, it exhibits a crossover from degenerate- to thermal-gas behavior, both of which are characterized by universal scaling laws linking the particle-loss rate to the total atom number N. In the degenerate and thermal regimes, the per-particle loss rate is ∝N^{2/3} and N^{26/9}, respectively. The crossover occurs at a universal kinetic energy per particle and at a universal time after the quench, in units of energy and time set by the gas density. By slowly sweeping the magnetic field away from the resonance and creating a mixture of atoms and molecules, we also map out the dynamics of correlations in the unitary gas, which display a universal temporal scaling with the gas density, and reach a steady state while the gas is still degenerate.

cond-mat.quant-gas, cond-mat.quant-gas, physics.atom-ph, quant-ph
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Phys Rev Lett
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American Physical Society (APS)
The Royal Society (uf110236)
European Office of Aerospace Research and Development (EOARD) (W911NF-15-1-0444)
Engineering and Physical Sciences Research Council (EP/N011759/1)
European Research Council (682285)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (704832)
Engineering and Physical Sciences Research Council (EP/P009565/1)