(a) The rocksalt crystal structure of CdO and EuO with space group (No. 255). (b) The Brillouin zone for the rocksalt structure. The time-reversal invariant momentum points are marked, for example, Γ (0, 0, 0), X(π, π, 0), and L(π, 0, 0). (c) The schematic of the (CdO)_n(EuO)_m superlattice. (d) The BZ of the (CdO)_n(EuO)_m superlattice. (e) The schematic of the (CdO)_n(EuO)_m quantum Well. Reprinted with permission from Ref. [26]. Copyright 2014 by the American Physical Society.