热Casimir相互作用中的各向异性：流体界面处捕获的椭球胶体
Anisotropies in thermal Casimir interactions: ellipsoidal colloids trapped at a fluid interface
摘要：
研究了两个椭球粒子在两相流体界面上的有效相互作用，这种有效相互作用是由界面的热涨落引起的。在该系统中，粒子对界面长程涨落的限制产生了涨落诱导力，它等价于Casimir型相互作用，在界面平面上是各向异性的。由于胶体相对于界面法线的位置和方向也可能波动，因此该系统是具有波动边界条件的卡西米尔效应的一个例子。在这里所采取的方法中，Casimir相互作用被重写为一个辅助电荷密度的波动多极矩之间的相互作用--这些波动耦合到接触线位置的多极矩的波动（由于胶体的可能的位置和取向波动）。我们得到明确的Casimir相互作用的行为在大距离任意椭球长宽比的表达式。如果胶体波动被抑制，在大距离的Casimir相互作用是各向同性的，有吸引力的和长范围的（双对数的距离）。然而，如果包括胶体波动，在大距离的卡西米尔相互作用的变化，在相反的距离幂律，并成为各向异性。如果只考虑胶体中心的垂直涨落，则主导幂为4，如果考虑取向涨落，则主导幂为8。
英文摘要：
We study the effective interaction between two ellipsoidal particles at the interface of two fluid phases which are mediated by thermal fluctuations of the interface. In this system the restriction of the long--ranged interface fluctuations by particles gives rise to fluctuation--induced forces which are equivalent to interactions of Casimir type and which are anisotropic in the interface plane. Since the position and the orientation of the colloids with respect to the interface normal may also fluctuate, this system is an example for the Casimir effect with fluctuating boundary conditions. In the approach taken here, the Casimir interaction is rewritten as the interaction between fluctuating multipole moments of an auxiliary charge density--like field defined on the area enclosed by the contact lines. These fluctuations are coupled to fluctuations of multipole moments of the contact line position (due to the possible position and orientational fluctuations of the colloids). We obtain explicit expressions for the behavior of the Casimir interaction at large distances for arbitrary ellipsoid aspect ratios. If colloid fluctuations are suppressed, the Casimir interaction at large distances is isotropic, attractive and long ranged (double--logarithmic in the distance). If, however, colloid fluctuations are included, the Casimir interaction at large distances changes to a power law in the inverse distance and becomes anisotropic. The leading power is 4 if only vertical fluctuations of the colloid center are allowed, and it becomes 8 if also orientational fluctuations are included.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
