A team of scientists found an evidence for unusual particle that, bizarrely, also its own antiparticle. It was first theorized 80 years ago but now looks like it might a reality. The findings conducted by scientists from Stanford University in California and the University of California.
The idea of a particle having its own antiparticle goes back to 1937 when Italian physicist Ettore Majorana first postulated the theory. He said, the class of fermions, which include protons, electrons, and neutrons, some particles should have their own antiparticles, which became known as Majorana particles.
An antiparticle is a particle that has the same mass as the regular particle, but an opposite electric or magnetic property. For example, the electron’s antiparticle is the positron. If the two encounter each other, they annihilate each other.
In this research, the team stacked thin films of two quantum materials together and sent an electrical current through them in a chilled vacuum chamber. The top film was a superconductor, and the bottom one was a magnetic topological insulator.
By sweeping a magnet over the stack, the team able to modifies the speed of electrons. At certain points, this caused what appeared to be Majorana quasiparticles to emerge in pairs along with electrons. One was always deflected away so that the flow of the individual quasiparticles could be measured.
According to Stanford physics Professor Giorgio Gratta, to clarify, the researchers note they didn’t exactly see Majorana particles. Rather, they saw essentially excitations in a material that behaves like Majorana particles,
Just as confusingly, it’s not clear if these particles can actually occur naturally. This particular type of Majorana quasiparticle has “chiral fermion”, which moves along a one-dimensional path in one direction.
The researchers are referring to this as “smoking gun” evidence of Majorana particles. It already thought that neutrinos might their own antiparticles, although separate research is continuing to find out if that’s the case.
This discovery concludes one of the most intensive searches in fundamental physics, which spanned exactly 80 years.