There is also the Majorana basis, in which all of the Dirac matrices are imaginary and spinors are real.
Some shielding experiments were conducted in the early 20th century by Majorana.
Ettore Majorana | Majorana | Majorana's equation | Majorana fermion |
Solution of Majorana's equation yields particles that are their own anti-particle, now referred to as Majorana Fermions.