Extended Data Fig. 4: Bulk conduction bands.
From: Spin-polarized spatially indirect excitons in a topological insulator
a, ARPES spectrum along \(\bar{\Gamma }-\bar{{\rm{M}}}\) direction for the n-type sample, measured at 40 K (left). The red dots in ARPES spectrum represent the peaks position extracted from the energy distribution curves (EDCs) from k1 to k2 and the black line represents the extracted band dispersion, corresponding to the bulk conduction band (CB). b, The EDC at the \(k{\prime} \) (see the dashed-line in panel a) where the both topological surface state (TSS) and CB are observed for the n- (top) and the p-type samples (bottom). The p-type’s EDC is extracted from non-equilibrium ARPES spectrum measured at 20 K, integrated over 0.2-1.6 ps of delay time (for better stats). c,d, EDCs for the n-type (c) and the p-type (d). The blue and red marks in right panel show the peaks position of the topological surface state and the bulk conduction band, respectively. e, Comparison of the bulk conduction bands between the n- and p-type samples. Note that energy levels are plotted with respect to the Dirac point energy (EDP) for a direct comparison. The error bars in a,e represent the uncertainties of peak positions from Lorentzian fits.
