Fig. 1: 2D surface Fermi surface (SFS) of NdBi.
From: Unconventional surface state pairs in a high-symmetry lattice with anti-ferromagnetic band-folding
Angle-resolved photo-electron spectroscopy (ARPES) at (a) T > TN and (b) T < TN with the unconventional surface state (SS) of hole Fermi arcs and SS electron pockets. The calculated SFS on (001) for (c) non-magnetic (NM) and anti-ferromagnetic (AFM) with (d–f) 1q, (g–i) 2q and (j, k) 3q wave vectors on different surfaces as labeled. The multi-q magnetic structures are shown in (d), (g), and (j). The orange (blue) spheres stand for Nd (Bi) atoms and the red arrows show the directions of Nd magnetic moments. The surface Brillouin zone for NM and 1q (001) is twice as large and rotated by 45 degree with respect to that for 2q and 3q (see Fig. 2b) for labels of high symmetry points). The 1q tetragonal (110) vertical diagonal surface in (f) is equivalent to the cubic (010) side surface. Blue, white and red colors stand for low, medium, and high density of states.
