Development of dynamical simulation method for quantum liquids and its extension to identical particle systems

我们发展了一种新的方法来计算量子液体的时间关联函数，最终目的是获得数值精确解。该方法基于团簇展开技术，整个系统的复时间传播子由少数几个粒子系统的复时间传播子构造而成，并得到了相当准确的计算。我们将这种方法应用于液氢和液氦的时间关联函数，并在较短的时间范围内成功地获得了收敛的结果。并将其推广到全同粒子系统(玻色粒子和费米粒子)，详细考察了粒子交换对时间关联函数的影响。

We have developed a novel approach to calculate time correlation functions for quantum liquids with the ultimate goal of obtaining numerically exact solutions. This method is based on the cluster expansion technique and the complex-time propagator of the whole system is constructed by those of a few particles systems, which are evaluated quite accurately. We have applied this method to time correlation functions of liquid para-hydrogen and liquid helium and succeeded in obtaining converged results for relatively short-time regions. The extension to identical particle systems(Bose and Fermi particles) is also carried and the effects of particle exchanges on the time correlation functions are examined in detail.