玻色-爱因斯坦凝聚(BEC)现象的研究

Researches on the Phenomena of Bose-Einstein Condensation(BEC)

玻色 -爱因斯坦凝聚 (BEC)的研究是当前物理学研究的一个新热点 ,国内外许多学者都开展了研究 .为探讨有关 BEC的普遍性质和规律以及影响 BEC的主要物理因素 ,我们研究了任意空间维数下 ,处于任意幂函数型外势约束中具有不同运动特征的玻色气体和费米气体的性质 .导出量子态密度、巨势及其它热力学函数的普遍解析表达式 ,提出赝体积和普遍热波长等新概念 ,首次求得有外势约束的玻色气体的态方程 ,并揭示了 BEC的一些新性质和确立了有关 BEC的两个新判据 ,同时还发现了 N0 / N～ T/ TC 曲线必为凸型的新规律 ,等等 .所得结果有助于深入了解 BEC这种新物态的特性 ,并为实验选择最佳外势阱的形式及其它物理参数提供一些新的理论依据 .此外还简要地介绍了国内外研究动态与进展以及本研究的前景 .

At present, the study on Bose Einstein condensation(BEC) has become a new hot point in physical researches. There are many scholars who have carried out researches at home and abroad in this area. In order to explore the general properties and laws of BEC and study how the properties of BEC depend on the physical parameters, we consider an ideal Bose or Fermi gas trapped in a generic power law potential in any dimensional space with a general dispersion relation. The universal analytical expressions of the density of states, grand potential and the other thermodynamic functions of the system were derived. The new concepts of the pseudovolume and general thermal wavelength were introduced, and the equation of state of the trapped Bose gas was derived for the first time. Moreover, two new criteria about BEC were established and some new laws, such as the curve of N 0/N～T/T c are always convex for Bose system in BEC phase, and so on, were found. All these results are useful for deep understanding the properties of the new matter state of BEC. On the basis of our results, the possibility of controlling the critical temperature and properties of BEC through setting up some physical parameters to facilitate the realization of BEC is exciting. In addition, the recent developments in BEC investigation and the prospects for BEC are introduced simply in this paper.