Fig. 4.

3D electronic structure of the Rashba-like splitting. a 3D E(k_x, k_y) map from angle-resolved photoemission spectroscopy (ARPES) data (hν = 9 eV). The black lines indicate the Rashba-split bands. Different surfaces correspond to constant-energy contours at different binding energies. b Calculated 3D electronic structure of PtBi₂ at the M point. The red lines indicate the Rashba-split dispersion along M–K (k_y) direction, while the blue lines indicate the Rashba-split dispersion along M–Γ (k_x) direction. c Calculated 3D electronic structure considering only pure Rashba SOC, taking effective masses from the ARPES data. The blue lines indicate the Rashba-split dispersion along M–K (k_y) direction, while the red lines indicate the Rashba-split dispersion along M–Γ (k_x) direction. Both red (blue) lines in b, c indicate dispersions with smaller (larger) band splitting. The gray surfaces with blue lines on them in b, c sketch out the constant-energy contours at different binding energies