Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195-1560, USA.
Phys Rev Lett. 2011 Jun 10;106(23):235303. doi: 10.1103/PhysRevLett.106.235303.
We use two fundamental theoretical frameworks to study the finite-size (shell) properties of the unitary gas in a periodic box: (1) an ab initio quantum Monte Carlo (QMC) calculation for boxes containing 4 to 130 particles provides a precise and complete characterization of the finite-size behavior, and (2) a new density functional theory (DFT) fully encapsulates these effects. The DFT predicts vanishing shell structure for systems comprising more than 50 particles, and allows us to extrapolate the QMC results to the thermodynamic limit, providing the tightest bound to date on the ground-state energy of the unitary gas: ξ(S)≤0.383(1). We also apply the new functional to few-particle harmonically trapped systems, comparing with previous calculations.
我们使用两个基本的理论框架来研究周期性盒子中幺正气体的有限尺寸（壳）性质：（1） 对包含 4 到 130 个粒子的盒子进行从头算量子蒙特卡罗（QMC）计算，为有限尺寸行为提供了精确和完整的描述，（2） 新的密度泛函理论（DFT）完全包含了这些效应。DFT 预测包含超过 50 个粒子的系统的壳结构为零，并且允许我们将 QMC 结果外推到热力学极限，从而为幺正气体的基态能量提供了迄今为止最严格的限制：ξ（S）≤0.383（1）。我们还将新的泛函应用于几个粒子的谐振子阱系统，并与之前的计算进行了比较。
