Physics News

Inside materials, the interactions between groups of electrons and atoms in the crystal lattice can give rise to a variety of interesting phenomena. Their collective behavior, especially at low temperatures, can give rise to quasiparticles: particle-like excitations that have strikingly different properties than the electrons that form them. Quasiparticles have been discovered that have behaviors predicted by particle physics, but have not been observed in particle collidors. Researchers in the Netherlands have now produced quasiparticles that act like Majorana fermions: electrically-neutral particles that are their own antiparticles, such that if two collide, they annihilate. The existence of Majorana fermions was first predicted in the 1930s, but no individual particles are known to behave that way. V. Mourik et al. found a quasiparticle version by constructing a very thin wire—a nanowire—of semiconductor material and connected it to a superconductor. The specific electronic properties of the