Fig. 2. Bulk Weyl fermion cones in TaP.

(A) SX-ARPES Fermi surface (FS) map at k_y = 0 in the k_z − k_x plane. (B) SX-ARPES Fermi surface map at k_z = W2 in the k_x − k_y plane, showing the W2 Weyl nodes. EXP, experimental. (C) Theoretical calculation of the same slice of the BZ at the same energy shows complete agreement with the SX-ARPES measurement. THY, theoretical. (D) First-principles calculations of the energy-momentum dispersion of the two sets of Weyl nodes, W1 and W2, in TaP. The two nodes are offset in energy by 64 meV. (E and F) Energy dispersion maps, E − k_//, for W1 and W2, respectively. (G and H) ARPES measured and theoretically calculated out-of-plane dispersion, E − k_z, for W2, which shows the linear dispersion of the Weyl cone along the out-of-plane direction. All data in (A) to (G) are obtained from Batch I. (I) Energy dispersion of the W2 Weyl cones from a sample in Batch II. We see the ± Weyl nodes more clearly for Batch II TaP, as labeled in (I).