Fermi气体在势阱中的最大囚禁范围与状态方程

Maximum trap range and equation of state for Fermi gas in potential trap

在Thomas-Fermi近似条件下,研究了n维广义幂律势阱中Fermi原子气体的最大囚禁范围,给出了n维势阱中气体的实际囚禁体积,导出了状态方程.结果表明,最大囚禁范围和囚禁气体压强不仅与势阱性质有关,也与自由理想Fermi系统的化学势有关.对三维球对称简谐势阱进行了应用,表明在Thomas-Fermi近似有效的前提下,当系统满足条件(kT/hω)2(16π2g/9N)2/3≤1时,压强对温度的依赖关系并不明显,而对粒子质量、粒子数及势场强度ω有较强的非线性依赖关系.

In the Thomas-Fermi semi-classical approximation, the maximal trap range and the real trap volume of ideal Fermi gas in an n-dimensional potential trap are gaven, and the relevant equations of state are derived. These results indicate that the maximal trap range and the real pressure of trapped gas are related to the potential field and the chemical potential of the free and ideal Fermi system. When the Thomas-Fermi approximate is valid and the condition（kT/hω）^2（16π^2g/9N）^2/3≤1 is satisfied, the application of the equation of state to three-dimensional spherical symmetry harmonic trap yields the result that the change of pressure is not obvious when the temperature changes, but the change of pressure is closely related to mass of particle, number of particles and the frequency of harmonic potential.