A particular kind of quasi-particle states, the Weyl fermions, were first discovered a few years ago in certain solids. Their specialty: They move through a material in a well ordered manner that practically never lets them collide with each other and is thus very energy efficient. This implies intriguing possibilities for the electronics of the future. Up to now, Weyl fermions had only been found in certain non-magnetic materials. Now however, for the very first time, scientists at the Paul Scherrer Institute PSI have experimentally proven their existence in another type of material: a paramagnet with intrinsic slow magnetic fluctuations. This finding also shows that it is possible to manipulate the Weyl fermions with small magnetic fields. It thus opens further possibilities to use them in spintronics, a promising development in electronics for novel computer technology. The researchers have published their findings in the scientific journal Science Advances.
Amongst the approaches that could pave the way to energy efficient electronics of the future, Weyl fermions could play a role. Found experimentally only inside materials as so-called quasi-particles, they behave like particles which have no mass. Predicted theoretically already in 1929 by the mathematician Hermann Weyl, their experimental discovery by scientists amongst other at PSI only came in 2015. So far, Weyl fermions had only been observed in certain non-magnetic materials. Now however, a team of scientists at PSI together with researchers in the USA, China, Germany and Austria also found them in a specific paramagnetic material. This discovery could bring a potential usage of Weyl fermions in future computer technology one step closer.
Image: The three PSI researchers Junzhang Ma, Ming Shi and Jasmin Jandke (from left to right) at the Swiss Light Source SLS, where they succeeded in proving the existence of Weyl fermions in paramagnetic material.
Credit: Paul Scherrer Institute/Markus Fischer