费米气体中两平行板间的卡西米尔力

Oscillating Casimir Force between Two Slabs in a Fermi Sea

研究了浸置于理想费米海中的两块平行板,在零温和非零温时的卡西米尔效应。研究发现,费米气体的卡西米尔效应与电磁场或者玻色气体有很明显的差异。电磁场和玻色气体的卡西米尔力会随着两板间距的增加而单调递减,然而,费米气体的卡西米尔力却会随着两板间距的变化而振荡。费米气体的卡西米尔力时而表现出吸引力,时而表现出排斥力,它对板间距的变化非常的敏感。此外,还发现费米气体卡西米尔力的振幅随着温度的增加而减小,这一特性与处于凝聚温度下的玻色气体完全相反,当温度区间处于T<Tc时,玻色气体的卡西米尔力随着温度的增加而线性增加,其中Tc为玻色-爱因斯坦凝聚温度。

The Casimir effect for two parallel slabs immersed in an ideal Fermi sea is investigated at both zero and nonzero temperatures. It is found that the Casimir effect for a Fermi gas is distinctly different from that for an electromagnetic field or a massive Bose gas. In contrast to the familiar result that the Casimir force decreases monotonically with the separation L of the two slabs for an electromagnetic field and a massive Bose gas, the Casimir force for a Fermi gas oscillates as a function of L. The Casimir force can be either attractive or repulsive, depending sensitively on the magnitude of L. In addition, it is found that the amplitude of the Casimir force for a Fermi gas decreases with increasing temperature, which is contrary to the case for a Bose gas since the bosonic Casimir force increases linearly with temperature in the region TTc, where Tcis the critical temperature of Bose-Einstein condensation.