Polarization of a fermion vacuum by a singular magnetic vortex: Spin and angular momentum

It has been found how the vacuum of a quantized spinor field in (2 + 1)-dimensional space is affected by the configuration of a static external magnetic field forming a singular vortex. The most general boundary conditions ensuring the self-adjointness of the two-dimensional Dirac Hamiltonian have been considered at the punctured singular point. It has been shown that a spin and an angular momentum are generated in a: vacuum, the latter being dependent, in contrast to other features of the vacuum, on the integral part of the vortex flux.