Fig. 3: Dramatic electronic reconstruction of ordered CeSb in AF phase.

a Three-dimensional FSs for P phase, and the folded one for b ab- and c c-domain according to the AF modulation (q = 1/2). The yellow-colored planes correspond to the k_x−k_y sheets at k_z = 0.2 Å⁻¹ detected by our laser-ARPES with hν = 7 eV (Supplementary Fig. 2). The insets schematically illustrate (red line) the  hole and (blue line) electron pockets in k_z−k_x plane (green frames in a–c) with (black line) the k_x cut line at k_z = 0.2 Å⁻¹ for our laser-ARPES. The FS maps experimentally observed at d 40 K (P phase) and 7.0 K (AF phase) for different domains, e ab- and f c-domain, which were taken at the different positions of the same cleaved surface. In d, we also observe the blurred photoelectron intensity outside the main signal due to the k_z broadening effect^14,51. g–i The E−k_x maps cut along the k_x line denoted by arrows in d–f. j–l The DFT bands cut along the comparable k_x line with g–i. The DFT bands in AF phase were computed with the backfolding of the bands of P phase into the deduced BZ (see b, c). The overall bands are shifted in energy with  −0.1  eV¹⁴ to compare the experimental results. The dispersions of the hole and electron bands are indicated by red- and blue-colored lines, respectively. The arrows in l highlight the band crossings which allow the hybridization. m–o The magnified laser-ARPES images within the E−k_x windows indicated by rectangles in g–i. In m and n, the band dispersion for P phase (dashed lines) was deduced by the peak position of the momentum distribution curves (circles in m). In o, the dispersions of the hole and electron bands are guided by red and blue lines, respectively.