Magnetic tunneling induced Weyl node annihilation in TaP

Understand

Weyl nodes are topological objects in three-dimensional metals.

• Their topological property can be revealed by studying the high-field transport properties of a Weyl semimetal.
• While the energy of the lowest Landau band (LLB) of a conventional Fermi pocket always increases with magnetic field due to the zero point energy, the LLB of Weyl cones remains at zero energy unless a strong magnetic field couples the Weyl fermions of opposite chirality.
• In the Weyl semimetal TaP, we achieve such a magnetic coupling between the electron-like Fermi pockets arising from the W1 Weyl fermions.