论文标题
与静态结构因子的冷凝物分数的估计
Estimation of the condensate fraction from the static structure factor
论文作者
论文摘要
我们提出了一种分析方法，用于估计密切相关的系统中的冷凝物分数$ n_0/n $，零温度静态结构因子因子$ s（{\ bf p}）$已知。提出的方法的优点是，它允许人们在宏观和介镜系统中预测一体密度矩阵（I）的远程行为，（ii）在零和低有限温度下的三维几何形状（III）中，在弱和低的有限温度下以及（IV），以及（IV），在弱和强烈相关的方向上。我们的方法是针对通过各种量子蒙特卡洛方法获得的精确值测试的，这些方法在许多强相关的系统中显示出极好的一致性。所提出的技术在数值模拟中也很有用，因为它允许人们将冷凝水分馏分推送到颗粒数量小至数百至数百的颗粒数的热力学极限。我们的方法对于从实验测量的静态结构因子$ s（{\ bf p}）$中提取冷凝物分数特别有价值，从而为估计$ n_0/n $提供了一种新的简单替代技术。我们分析了超级流体氦气的$ s（{\ bf p}）$的可用实验数据，并与$ n_0/n $的实验值找到了一个很好的协议。
We present an analytical method to estimate the condensate fraction $n_0/n$ in strongly correlated systems for which the zero-temperature static structure factor $S({\bf p})$ is known. The advantage of the proposed method is that it allows one to predict the long-range behavior of the one-body density matrix (i) in macroscopic and mesoscopic systems, (ii) in three- and two-dimensional geometry, (iii) at zero and low finite temperature, and (iv) in weakly and strongly correlated regimes. Our method is tested against exact values obtained with various quantum Monte Carlo methods in a number of strongly correlated systems showing an excellent agreement. The proposed technique is also useful in numerical simulations as it allows one to extrapolate the condensate fraction to the thermodynamic limit for particle numbers as small as tens to hundreds. Our method is especially valuable for extracting the condensate fraction from the experimentally measured static structure factor $S({\bf p})$, thus providing a new simple alternative technique for the estimation of $n_0/n$. We analyze available experimental data for $S({\bf p})$ of superfluid helium and find an excellent agreement with the experimental value of $n_0/n$.
