Elusive particle shows up in ‘semimetal’

Weyl fermions detected in tantalum arsenide

A kind of particle first predicted to exist before the discovery of Pluto has been spotted on Earth within a compound of tantalum and arsenic.

The newly discovered particles, known as Weyl fermions, resemble massless electrons that dart around and through the material in unusual and exciting ways, researchers report July 16 in Science.