The Legendre Collocation Spectral Method for the Ground State Solutions of the Bose-Einstein Condensates
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摘要: 近年来, 有关Bose-Einstein凝聚态基态解的实验研究已经取得了一系列重要的成果. 该文在相关研究成果的基础上, 首先通过降维和无量纲化方法将Bose-Einstein凝聚态基态解问题转换成能量泛函极值问题, 在离散该泛函时, 尝试使用Legendre配置谱方法离散该能量泛函的一维和二维情形. 其次, 对该能量泛函极小值问题进行了数值模拟. 最后,通过分析实验数据结果和图像得出,针对非旋转的Bose-Einstein凝聚态的基态解问题可以使用Legendre配置谱方法来求解, 且数值结果的误差较小.
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关键词:
- Bose-Einstein凝聚态 /
- Legendre配置谱方法 /
- 数值计算
Abstract: In recent years, a series of important achievements have been made in the experimental study of the ground state solutions of the Bose Einstein condensates. First, the ground state solution problem of the Bose Einstein condensate was converted into the extreme value problem of energy functional with the dimensionless method. In the discretization of the energy functional, the Legendre collocation spectral method was used in the 1D and 2D cases. Second, the energy functional minimum problem was numerically simulated. The analyses of the experimental data and graphs show that, the Legendre collocation spectral method is applicable to the ground state solution of the non-rotating Bose Einstein condensate, and the errors of the numerical results are very small. -
表 1 一维情况下, 改变N的大小, 误差ε的变化情况
Table 1. In the 1D case, changes of error ε with N
N 10 20 30 40 50 error ε 6.46E-1 1.79E-1 4.67E-2 1.10E-2 1.10E-3 表 2 二维情况下, 改变N的大小, 误差ε的变化情况
Table 2. In the 2D case, changes of error ε with N
N 10 20 30 40 50 error ε 3.65E-1 2.23E-2 5.38E-4 9.31E-7 1.22E-9 表 3 一维情况下Legendre配置谱方法的能量值Eβ(ϕg)和Fourier谱方法的能量值Eβ(ϕgFP)与β之间的变化情况
Table 3. Energy value Eβ(ϕg) of the Legendre collocation spectrum method and energy value Eβ(ϕgFP) of the Fourier spectrum method in the 1D case, changing with β
β 0 5 10 100 1 000 Eβ(ϕg) 0.499 9 1.316 0 1.947 2 8.508 5 39.322 4 Eβ(ϕgFP) 0.500 0 1.316 1 1.947 1 8.508 5 39.322 4 表 4 二维情况下Legendre配置谱方法的能量值Eβ(ϕg)和Fourier谱方法的能量值Eβ(ϕgFP)与β之间的变化情况
Table 4. Energy value Eβ(ϕg) of the Legendre collocation spectrum method and energy value Eβ(ϕgFP) of the Fourier spectrum method in the 2D case, changing with β
β 0 5 10 100 1 000 Eβ(ϕg) 1 1.437 1 1.611 7 3.983 6 12.001 Eβ(ϕgFP) 0.968 7 1.501 1 1.697 1 4.004 0 12.001 -
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