Collective oscillations of a classical gas confined in harmonic traps
Collective oscillations of a classical gas confined in harmonic traps
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谐波陷阱中经典气体的集体振荡
DOI：
10.1103/physreva.60.4851
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发表时间：
1999
影响因子：
2.9
通讯作者：
S. Stringari
中科院分区：
文献类型：
--
作者：
David Guéry;F. Zambelli;J. Dalibard;S. Stringari
从玻尔兹曼方程出发，计算了简谐势约束下经典气体集体振动的频率和阻尼。在存在球形和轴向变形陷阱的情况下，同时考虑了单极和四极模。松弛时间的计算采用高斯变换，它显式地解释了速度空间中四极形变的发生。我们的方法提供了流体动力学和无碰撞区域之间的转换的明确描述。这些预测与在硬球气体中进行的分子动力学模拟的结果非常一致。@S1050-2947~99 02312-4#
Starting from the Boltzmann equation, we calculate the frequency and the damping of the collective oscillations of a classical gas confined by a harmonic potential. Both the monopole and quadrupole modes are considered in the presence of spherical as well as axially deformed traps. The relaxation time is calculated using a Gaussian ansatz which explicitly accounts for the occurence of quadrupole deformations in velocity space. Our approach provides an explicit description of the transition between the hydrodynamic and collisionless regimes. The predictions are in very good agreement with the results of a molecular-dynamics simulation carried out in a gas of hard spheres. @S1050-2947~99!02312-4#