@misc{bittencourt2015entanglement,
  title={Entanglement of Dirac bi-spinor states driven by Poincaré classes of $\mbox{SU}(2) \otimes \mbox{SU}(2)$ coupling potentials},
  author={Victor A. S. V. Bittencourt and Alex E. Bernardini},
  year={2015},
  eprint={1511.07047},
  archivePrefix={arXiv},
  primaryClass={quant-ph},
  doi={10.1016/j.aop.2015.11.004},
  url={https://arxiv.org/abs/1511.07047}
}