Figure 1: A schematic diagram of Majorana particles lined up in two opposing magnetic fields (red) that interact with a superconducting topological insulator (blue). At the gap between the magnets, the superconductor is weakened and magnetic field lines assemble in a periodic chain to which Majorana particles (yellow) attach. Credit: Reproduced, with permission, from Ref. 1 2010 The American Physical Society
The matter that makes up the universe consists of particles such as electrons and protons, as well as their counterparts known as antiparticles. Particles and antiparticles that collide, however, annihilate each other in an intense flash of energy. Nevertheless, the Italian physicist Ettore Majorana proposed that some particles could exist that are their own antiparticles although physicists are yet to observe such particles.