2026/07/24 by Hui-Dong Huang, Qi Meng, Zhi-Bin Wang +3
#physics.acc-ph #physics.plasm-ph #quant-ph
Rotational symmetry protects the topological charge of on-axis electron vortices but not of off-axis vortices. We identify an additional SU(1,1) dynamical invariant that guarantees conservation of their intrinsic orbital angular momentum within the near-axis approximation. First-principles simulations of an off-axis electron vortex traversing a Glaser lens confirm this prediction, establishing a robust transport mechanism in axisymmetric nonuniform magnetic fields.