Figure 2: Ten lowest bands in the spin-wave spectrum of a 2D Co/Fe composite with lattice constant (a) 50 nm and (b) 100 nm, calculated along the high-symmetry line in the 2D Brillouin zone (cf. Figure 1(b)). Circular cross section of the rods and filling fraction are assumed in both cases. Shaded areas represent magnonic gaps. Note the plots differ in frequency range: 0 GHz to 80 GHz in (a), and 10 GHz to 35 GHz in (b).