Figure 3: Rashba–Zeeman (RZ) splitting: experiment, theory and consequences for 3D Fermi surface.

(a) Zoomed-in ARPES data from Fig. 2f (second-derivative plots from red rectangle area in Fig. 2b) compared with ab initio Ge1−xMnxTe calculations for selected Mn dopings in b; each fitted to a simplified RZ gas model (red/blue lines) and more accurate Dirac fermion model (light-blue lines). The best-fit parameters of the Rashba parameter αR and the Zeeman gap ΔZ are displayed in the corresponding lower right hand panels. The αR error bars were obtained from varying the fit parameters. (c) 3D Fermi surfaces for three different chemical potentials μ.