Abstract
AbstractSpin angular momenta play important roles in light–matter interactions, leading to the emergence of the spin Hall effect and topological quasiparticles in modern optics. The typical approach is to decompose the spins of plane electromagnetic waves into longitudinal and transverse components, yet this description is not easily transferable to more structured electromagnetic environments. Here, we developed a field theory to reveal the physical origin and topological properties of longitudinal and transverse spins for arbitrary electromagnetic waves (including water waves and acoustic waves) in both near-field and free space. For electromagnetic waves carrying intrinsic helicity, we observed the emergence of helicity-dependent transverse spin possessing helicity-dependent spin-momentum locking. To verify that the number of spin-momentum locking states coincides with the spin Chern number, we experimentally measured the three-dimensional spin angular momentum densities of Bloch-type optical skyrmions. Our findings yield valuable insight for constructing spin-based field theory and exploiting optical topological quasiparticle-based applications.
Funder
National Natural Science Foundation of China
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy
Reference59 articles.
1. Fert, A. Nobel Lecture: Origin, development, and future of spintronics. Rev. Mod. Phys. 80, 1517–1530 (2004).
2. Bliokh, K. Y., Rodríguez-Fortuño, F. J., Nori, F. & Zayats, A. V. Spin–orbit interactions of light. Nat. Photon 9, 796–808 (2015).
3. Yuan, W. et al. Observation of elastic spin with chiral meta-sources. Nat. Commun. 12, 6954 (2021).
4. Wang, S. et al. Spin-orbit interactions of transverse sound. Nat. Commun. 12, 6125 (2021).
5. Long, Y., Ren, J. & Chen, H. Intrinsic spin of elastic waves. Proc. Natl Acad. Sci. USA 115, 9951–9955 (2018).
Cited by
3 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献