Theory of the kinetic coefficients of the atomically rough surface of 4He crystals
Theory of the kinetic coefficients of the atomically rough surface of 4He crystals
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4He晶体原子粗糙表面的动力学系数理论
DOI：
10.1051/jphys:01983004406072300
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
D. Edwards
中科院分区：
文献类型：
--
作者：
R. Bowley;D. Edwards
本文计算了hcp ~ 4 He晶体原子粗糙表面的生长系数K（单位化学势差的生长速度）和昂萨格交叉系数b_1和b_2（生长与热流耦合）。该计算是基于Andreev和Parshin提出的前提，即增长受到声子和声子与界面碰撞的限制。计算的K值与Keshiskev等人从融化-冻结波阻尼中得到的K值进行了比较。该理论假设的激励是在弹道制度，其平均自由程是大的熔化-冻结波的波长相比。在实验中，只有声子满足这个条件，但理论与数据相一致，即使当旋子散射很重要时。不可逆热力学要求交叉系数b1和B 2相等。这是通过直接计算得出的。b1和b2的值取决于两个积分的比率在声子传输系数和它的传输的两个模型进行评估。该理论与最近对b1的测量结果相当吻合。在流体动力学制度，其中的自由路径是短的耗散的计算表明，融化冻结波的阻尼应该有不同的依赖频率相比，弹道制度。
The growth coefficient K (the velocity of growth per unit chemical potential difference) and the Onsager cross-coefficients b1 and b2, coupling growth and heat flow, are calculated for atomically rough surfaces of hcp 4He crystals. The calculation is based on the premise, suggested by Andreev and Parshin, that growth is limited by the collision of phonons and rotons with the interface. The calculated K is compared with that obtained by Keshiskev et al. from the damping of melting-freezing waves. The theory assumes that the excitations are in the ballistic regime where their mean free path is large compared to the wavelength of the melting-freezing waves. In the experiment only the phonons satisfy this condition, yet the theory agrees with the data even when roton scattering is important Irreversible thermodynamics requires that the cross coefficients b1 and b 2 be equal. This is shown by direct calculation. The value of b1 and b2 depends on the ratio of two integrals over the phonon transmission coefficient and it is evaluated for two models of the transmission. The theory agrees fairly well with a recent measurement of b1. A calculation of the dissipation in the hydrodynamic regime, where the free path is short, shows that the damping of melting-freezing waves should have a different dependence on frequency compared to the ballistic regime.