Experimental discovery of Weyl semimetal TaAs

Understand

Weyl semimetals are a class of materials that can be regarded as three-dimensional analogs of graphene breaking time reversal or inversion symmetry.

• Electrons in a Weyl semimetal behave as Weyl fermions, which have many exotic properties, such as chiral anomaly and magnetic monopoles in the crystal momentum space.
• The surface state of a Weyl semimetal displays pairs of entangled Fermi arcs at two opposite surfaces.
• However, the existence of Weyl semimetals has not yet been proved experimentally.