Entanglement capabilities of the spin representation of (3+1)D-conformal   transformations
  Relying on a mathematical analogy of the pure states of the two-qubit system of quantum information theory with four-component spinors we introduce the concept of the intrinsic entanglement of spinors. To explore its physical sense we study the entanglement capabilities of the spin representation of (pseudo-) conformal transformations in (3+1)-dimensional Minkowski space-time. We find that only those tensor product structures can sensibly be introduced in spinor space for which a given spinor is not entangled. 
K. Scharnhorst (Vrije Universiteit Amsterdam)
quant-ph hep-th math-ph math.MP