Distance-Dependent Sign Reversal in the Casimir-Lifshitz Torque
Distance-Dependent Sign Reversal in the Casimir-Lifshitz Torque
复制标题
Casimir-Lifshitz 扭矩中距离相关的符号反转
DOI：
10.1103/physrevlett.120.131601
复制
发表时间：
2018
影响因子：
8.6
通讯作者：
Persson, Clas
中科院分区：
文献类型：
--
作者：
Thiyam, Priyadarshini;Parashar, Prachi;Shajesh, K. V.;Malyi, Oleksandr I.;Boström, Mathias;Milton, Kimball A.;Brevik, Iver;Persson, Clas
在两个双轴极化各向异性平面板之间的卡西米尔-利夫希茨转矩在其旋转意义上表现出非平凡的符号反转。板面之间的临界距离标志着这一反转，其特征是沿两个主轴的平面内极化率相等的频率。这两种材料试图将它们的极化主轴在下面一个方向上对齐，而在上面，它们的轴试图对齐旋转垂直于它们之前的最小能量方向。符号反转在非延迟极限中消失。我们在相对极化率差异很小的情况下得到的微扰结果与单轴材料的精确理论非常吻合。我们举例说明了黑磷和磷烯的结果。
The Casimir-Lifshitz torque between two biaxially polarizable anisotropic planar slabs is shown to exhibit a nontrivial sign reversal in its rotational sense. The critical distancebetween the slabs that marks this reversal is characterized by the frequencyat which the in-planar polarizabilities along the two principal axes are equal. The two materials seek to align their principal axes of polarizabilities in one direction below, while abovetheir axes try to align rotated perpendicular relative to their previous minimum energy orientation. The sign reversal disappears in the nonretarded limit. Our perturbative result, derived for the case when the differences in the relative polarizabilities are small, matches excellently with the exact theory for uniaxial materials. We illustrate our results for black phosphorus and phosphorene.