  The framework of Wigner functions for the canonical pair angle and orbital
angular momentum, derived and analyzed in 2 recent papers [H. A. Kastrup,
Phys.Rev. A 94, 062113(2016) and Phys.Rev. A 95, 052111(2017)] is applied to
elementary concepts of quantum information like qubits and 2-qubits, e.g.,
entangled EPR/Bell states etc. Properties of the associated Wigner functions of
such superposed states (pure and mixed) are discussed and illustrated. The
Wigner functions of ERP/Bell states are distinguished by their topologically
"twisted" domain on the configuration subspace S^1xS^1, a torus, of the total
phase space. Like the applications of Wigner functions in quantum optics the
results presented in the present paper may be useful for the description and
analysis of quantum information experiments with orbital angular momenta of
light beams or electron beams, respectively.
