SPICE Workshop on Spin textures: Magnetism meets Plasmonics, July 23rd - 25th 2024
Guy Bartal
The Erna and Andrew Viterbi faculty of Electrical and Computer Engineering, Haifa, Israel
Photons are known to carry angular momentum in the forms of spin, related to the circular polarization, and orbital angular momentum (OAM), determined by the shape of its wavefunction. In paraxial optics, the two forms of angular momentum are separable, such that a photon can be imprinted with any integer quanta of OAM irrespective of its spin. Nanophotonic states, however, intrinsically possess a three-dimensional vector wavefunction causing the spin and OAM to be inseparable. Therefore, such states, e.g., surface plasmons, can only be defined by their total angular momentum (TAM), resulting in both classical and quantum implications. Those include unique conservation laws, which apply to both circularly-symmetric and periodic nanophotonic states, well-recognized field textures – such as optical skyrmions, and new quantum correlations of photon pairs.
I will review our experimental progress in all these aspects which include the first demonstration of optical skyrmions, direct imaging of the vector-field content of plasmonic fields and non-classical correlations between plasmon pairs entangled in their total angular momentum.