These tungsten ditelluride crystals behave as insulators for current applied in some directions and as conductors for current applied in other directions. The researchers found that this behavior is due to a newly theorized particle, the type-II Weyl fermion. Credit: Wudi Wang and N. Phuan Ong, Princeton University --------------------------------------------------------------------------------------------------------------------------------------- An international team of researchers has predicted the existence of a new type of particle called the type-II Weyl fermion in metallic materials. When subjected to a magnetic field, the materials containing the particle act as insulators for current applied in some directions and as conductors for current applied in other...