arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2108.00725physics.optics
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一般电磁场的自旋分解及其拓扑性质

Spin decomposition and topological properties in a generic electromagnetic field

Peng Shi, Aiping Yang, Xiaojin Yin, Luping Du, Xinrui Lei, Xiaocong Yuan

摘要:

电磁自旋(包括纵向自旋和横向自旋)在光与物质相互作用中起着重要的作用。在这里,我们制定了一个统一的方程,揭示的物理起源和拓扑性质的纵向和横向自旋在一个通用的电磁场。该方程普遍地揭示了横向自旋与动力学动量锁定,起源于场的横向不均匀性,而与螺旋相关的纵向自旋方向与局域波矢平行。值得注意的是,一个隐藏的特殊的螺旋依赖的横向自旋具有螺旋依赖的自旋动量锁定被发现和锁定状态的数量与非平凡的拓扑自旋陈数一致。此外,这种决定反螺旋分量的自旋与Berry曲率密切相关。通过测量聚焦构型中的三维自旋分量,实验证明了这一发现,这将加深对自旋基础物理的理解,并为手征量子光学应用开辟一条途径。

英文摘要:

Electromagnetic spins, including longitudinal and transverse ones, have been playing important roles in light-matter interactions. Here, we formulate a unified equation to uncover the physical origins and topological properties of longitudinal and transverse spins in a generic electromagnetic field. The equation reveals universally that the transverse spin is locked with the kinetic momentum and originated from the transverse inhomogeneities of field, whereas the helix-dependent longitudinal spin orients parallel to the local wavevector. Remarkably, a hidden extraordinary helix-dependent transverse spin possessing helix-dependent spin-momentum locking is discovered and the number of locking states consistent with the nontrivial topological spin Chern number. Furthermore, this spin which determines the inverted helical components is related to the Berry curvature closely. The findings, which are demonstrated experimentally by measuring the three-dimensional spin components in the focusing configuration, will deepen the understanding the underlying physics of spins and open an avenue for chiral quantum optical applications.

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。

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