A particle like slow light

A remarkable discovery was made at TU Wien recently, when particles known as 'Weyl fermions' were discovered in materials with strong interaction between electrons. Just like light particles, they have no mass but nonetheless they move extremely slowly. There was great excitement back in 2015, when it was first possible to measure these 'Weyl fermions' - outlandish, massless particles that had been predicted almost 90 years earlier by German mathematician, physician and philosopher, Hermann Weyl. Now, once again, there has been a breakthrough in this field of research, with researchers at TU Wien being the first to successfully detect Weyl particles in strongly correlated electron systems - that is, materials where the electrons have a strong interaction with each other. In materials like this, the Weyl particles move extremely slowly, despite having no mass. The discovery should now open the door to an entirely new area of physics, and enable hitherto unimagined material-physical effects. Quasiparticles: only possible in a solid state - After physician Paul Dirac had arrived at his Dirac equation in 1928, which can be used to describe the behaviour of relativistic electrons, Hermann Weyl found a particular solution for this equation - namely for particles with zero mass, or 'Weyl fermions'.