Simulation Studies of Quantum Systems

量子力学多体系统的研究一直是统计物理理论研究的一个重要热点。他们使用格林函数蒙特卡罗和路径积分蒙特卡罗来提供关于量子系统，特别是量子流体和晶体性质的详细微观信息。他们将继续研究二维和三维量子流体和固体的结构，以及T = 0及以上时融-冻转变的性质。他们将强调改进固体试验波函数的发展。将继续研究系统冻结时高阶相关函数的变化。他们打算计算诸如二维和三维弹性常数以及二维拓扑缺陷的作用等性质。计算结果将借助经验理论和密度泛函理论进行解释。他们还将尝试构建现象学密度矩阵来描述玻色流体，并研究汤川量子系统的压力熔化。另一个新领域将是研究非均匀系统的性质，包括具有液-气界面的平板、量子涡旋、具有大角动量的液滴、液氦4中的杂质以及吸附在衬底上的二维系统。将继续研究各种提出的氦-氦电位的影响。

The investigation of quantum-mechanical many-body systems has been an important focus of theoretical researchers in statistical physics. They use Green's function Monte Carlo and path integral Monte Carlo to provide detailed microscopic information about the properties of quantum systems, especially quantum fluids and crystals. They will continue to study the structure of two- and three- dimensional quantum fluids and solids and the nature of the melting-freezing transition at T = 0 and above. They will emphasize the development of improved solid trial wavefunctions. Studies of the changes in higher-order correlation functions as the system freezes will be continued. They intend to calculate properties such as elastic constants in two and three dimensions and the role of topological defects in two dimensions. The computational results will be interpreted with the help of empirical and of density-functional theories. They will also attempt to construct phenomenological density matrices to describe Bose fluids and to investigate pressure melting of Yukawa quantum systems. Another new area will be the investigation into the properties of inhomogeneous systems, including slabs with liquid-vapor interfaces, quantum vortices, droplets having large angular momenta, impurities in liquid Helium 4, and two-dimensional systems adsorbed on a substrate. Studies will be continued of the effects of various proposed Helium-Helium potentials.