Fig. 6
From: Topological sound
Weyl semimetal and topological charged nodal surface semimetal. a, e Show the tight-binding model of a system possessing Weyl points and a charged nodal surface, respectively. b, f Show the topological charge distribution in the reciprocal space for the tight-binding model in a, e, respectively, where the red and blue spheres represent Weyl points with charge +1 and −1, respectively, and the red surface represents a nodal surface with topological charge +2. Some high symmetry points in the first Brillouin zone are also labeled. c shows the band structure, where t0 = 1 and tc = 0.2 are used. Here red and blue correspond to the tight-binding model in a, e, respectively. d shows the Chern number as a function of kz, which changes at kz = 0 and kz = π
