Fig. 4: Electronic structure of β-Bi4I4 on the (100) and (001) surface.
From: Topological phase transition in quasi-one-dimensional bismuth iodide Bi4I4
a, b ARPES spectra of β-Bi4I4 at \({\bar{\Gamma }}_{100}\) and \(\bar{Z}\) point on the (100) surface, respectively. c, d ARPES spectra of β-Bi4I4 at \({\bar{\Gamma }}_{001}\) and \(\bar{M}\) point on the (001) surface, respectively. The red arrow indicates the energy gap at the \(\bar{M}\) point. The spectra were measured along the chain direction at 316 K using LH-polarized 7-eV laser.
