Figure 1.

Four methods of producing neutron spin-orbit states. The phase and intensity profiles of the output states, post-selected on the spin state correlated to the OAM, are shown on the right. (a) An incoming neutron wavepacket in a coherent superposition of the two spin eigenstates passes through a magnetic SPP which is made out of a material with equal magnetic and nuclear scattering lengths, thereby inducing an azimuthally varying phase for only one spin state. (b) A spin-polarized neutron wavepacket passes through a quadrupole magnetic field which induces the spin-orbit state [18].After transversing the quadrupole field, the intensity profile of the spin state correlated to the OAM has a ring shape. (c) A sequence of quadrupoles with appropriate length and orientation acts as a BB1 pulse which increases the radii at which the spin and OAM are maximally entangled. (d) In analogy to the LOV prism pairs capable of generating lattices of optical spin-orbit states [34], a sequence of magnetic prisms can be used to approximate the quadrupole operator and produce a lattice of neutron spin-orbit states.