Energy band of the Rashba wire with a superlattice structure. The spatial periodicity of the oscillating RSOC is described in each panel ((a) N = 3, (b) N = 5, (c) N = 8, (d) N = 11). The energy gaps are marked by dotted-line circles and the Chern numbers of three subbands are marked in each panel and they have the same Chern-number structures.