Weyl fermions are a type of elementary particle that arise in certain materials known as Weyl semimetals. They are massless particles that behave like chiral fermions, meaning they have a specific handedness or spin orientation. This unique property allows them to move through a material without scattering, leading to potential applications in electronics and quantum computing. These particles were first theorized by physicist Hermann Weyl in 1929 and have since been observed in various materials. Their discovery has opened new avenues in condensed matter physics, as they exhibit unusual behaviors such as the chiral anomaly, which can influence the conductivity of materials.