Figure 4: Schematic of the spin-polarized surface state dispersion in the TKI SmB6.
From: Direct observation of the spin texture in SmB6 as evidence of the topological Kondo insulator

The blue and green curved surfaces centred at the and
points represent the α- and β-bands, respectively. The plane sitting below represents the bulk f states. The spin polarizations of the β-band are indicated with red arrows. The shape and size of the α-band are from refs 7, 17. The blue dashed lines indicate the first SBZ.