论文标题
超速玻璃气体的自旋蒸馏冷却
Spin distillation cooling of ultracold Bose gases
论文作者
论文摘要
我们研究了骨气原子的旋转气体的旋转蒸馏，并在$ {}^{52} $ cr和$^{23} $ na原子中找到两种不同的机制，它们都可以有效冷却。第一个机制涉及偶极散射到最初无占空的自旋状态，并且仅在阈值磁场以上冷却。第二种是通过将热云平衡放到空自旋状态下进行的，从而减少了其在初始组件中的比例。它仅冷却阈值磁场。该技术最初是在实验中针对偶极气的实验证明的[B. Naylor等人，物理。莱特牧师。 115，243002（2015）]，而在这里我们进一步发展了该概念，并对所涉及的物理和局限性提供了深入的理解。通过数值模拟，我们揭示了所涉及的机制，并证明了旋转蒸馏循环可以重复几次，每次导致热原子分数的显着额外减少。还确定了磁场的阈值和可实现温度的预测。
We study the spin distillation of spinor gases of bosonic atoms and find two different mechanisms in ${}^{52}$Cr and $^{23}$Na atoms, both of which can cool effectively. The first mechanism involves dipolar scattering into initially unoccupied spin states and cools only above a threshold magnetic field. The second proceeds via equilibrium relaxation of the thermal cloud into empty spin states, reducing its proportion in the initial component. It cools only below a threshold magnetic field. The technique was initially demonstrated experimentally for a chromium dipolar gas [B. Naylor et al., Phys. Rev. Lett. 115, 243002 (2015)], whereas here we develop the concept further and provide an in-depth understanding of the required physics and limitations involved. Through numerical simulations, we reveal the mechanisms involved and demonstrate that the spin distillation cycle can be repeated several times, each time resulting in a significant additional reduction of the thermal atom fraction. Threshold values of magnetic field and predictions for the achievable temperature are also identified.
