Fig. 3

Topological surface states and Fermi arcs. a The calculated (010)-surface band structure of the stressed KHgBi with Δc/c₀ = 0.115. (see “Method”). The red color represents the bulk projected bands. The upper inset is a zoom-in of the calculated surface band structure along \(- \overline Z \to \overline \Gamma \to \overline X\) with ±i indicating the \(\hat M_z\) eigenvalues of the surface states. The lower inset is a schematic illustration of the surface band structure along \(- \overline X \to \overline \Gamma \to \overline X\) with blue and red lines representing, respectively, positive and negative eigenvalues of \(\hat M_z\). b Constant energy cut at the Fermi energy (i.e., the Fermi surface). The two yellow dots indicate the position of the bulk-projected Dirac nodes, which are connected by a pair of Fermi arcs labeled by I and II