Orbital Angular Momentum Generation in Schwinger Scattering from Perfect Quartz

Static electric fields have been suggested as a spin to orbital angular momentum converter in neutrons. Initial calculations showed that the field required to facilitate significant conversion to longitudinal orbital angular momentum is prohibitively high for lab power supplies. In this work we exploit the intra-atomic nuclear electric field in the periodic structure of perfect single crystals, specifically quartz, which can be orders of magnitude larger than lab fields. We calculate the Bragg and Laue diffracted wavefunctions of thermal neutrons and back-diffracted neutrons and demonstrate spin to orbital angular momentum conversion. Finally we report on a thermal neutron Bragg diffraction experiment from [110] quartz confirming our results.