Author(s): F. M. Jiang, X. F. Li, Y. S. Zeng, Y. F. Bai, C. P. Liu, J. X. Li, Y. Tian, and R. X. Li Manipulating the spin of ultrarelativistic charged particle beams is a cornerstone of high-energy physics, yet its practical implementation has been limited by intrinsic energy dependence and a lack of universality across particle species. Here, we introduce the concept of a “unipolar surface wave s… [Phys. Rev. Lett. 137, 125001] Published Tue Sep 15, 2026