Fig. 1

a Pyrochlore lattice. The balls and sticks denote the sites and bonds, respectively. This is the A-site sublattice of A₂B₂O₇ pyrochlore structure. b Band dispersion of the tight-binding model (Eq. 1) on the pyrochlore lattice. The parameters are set as ε = − 0.2 and t = − 0.03. The unit of energy is eV. The number in (b) denotes the index of the irreducible representation, see ref. [34]