论文标题
弹性旋转和轨道角动量
Elastic Spin and Orbital Angular Momenta
论文作者
论文摘要
由弹性波的旋转和轨道角动量的最新理论和实验兴趣的动机，我们在各向同性弹性介质中重新审视了规范波动动量，自旋和轨道角动量。我们表明，这些数量通过简单的通用表达来描述，这与[G. J. Chaplain等人，物理学。莱特牧师。 128，064301（2022）]，不需要分离波场的纵向和横向部分。对于圆柱弹性模式，对总（自旋+轨道）角动量的归一化Z组分进行量化，并等于该模式的方位角量子数，而轨道和旋转部分由于旋转轨道的旋转型气相效果而未量化。与上述文章的主张相反，纵向，横向和“混合”对角动量的贡献同样重要，不能忽略。作为一般形式主义的另一种应用，我们计算表面雷利波的横向自旋角动量。
Motivated by recent theoretical and experimental interest in the spin and orbital angular momenta of elastic waves, we revisit canonical wave momentum, spin, and orbital angular momentum in isotropic elastic media. We show that these quantities are described by simple universal expressions, which differ from the results of [G. J. Chaplain et al., Phys. Rev. Lett. 128, 064301 (2022)] and do not require separation of the longitudinal and transverse parts of the wavefield. For cylindrical elastic modes, the normalized z-component of the total (spin+orbital) angular momentum is quantized and equals the azimuthal quantum number of the mode, while the orbital and spin parts are not quantized due to the spin-orbit geometric-phase effects. In contrast to the claims of the above article, longitudinal, transverse, and `hybrid' contributions to the angular momenta are equally important and cannot be neglected. As another application of the general formalism, we calculate the transverse spin angular momentum of a surface Rayleigh wave.
