Research on the correlation between spin–orbit entangled states and the spin–orbit interaction of light

Abstract

Two kinds of phenomena with the same essence may be correlative. Exploring this correlation can help us generate new ideas. Light can carry three types of angular momentum: The rotating electromagnetic field with circularly polarized will produce spin angular momentum (SAM); The vortex light with helical wavefronts will carry intrinsic orbital angular momentum (IOAM); Light, not traveling through the coordinate origin, will carry extrinsic orbital angular momentum (EOAM). The interaction between SAM and EOAM will produce a spin Hall effect of light. The interaction between SAM and IOAM will lead to mutual conversion between them. SAM and EOAM, as well as SAM and IOAM, can also form spin–orbit entangled states. Therefore, the spin–orbit interaction and corresponding entangled states of light must have some correlations. This work studied the relationship between the spin Hall effect and the spin–orbit entangled state, and the relationship between the conversion efficiency of spin–orbit angular momentum and the spin–orbit entangled state. This work can provide new enlightenment to the study of entangled states, which can help the cross-disciplinary application of quantum entanglement with other knowledge.