Fig. 5: Temperature evolution of the (100) surface states across the structural transition.
From: Topological phase transition in quasi-one-dimensional bismuth iodide Bi4I4
a–k ARPES spectra of the (100) surface states at the \({\bar{\Gamma }}_{100}\) point of α-Bi4I4 (a–g) and \(\bar{Z}\) point of β-Bi4I4 (h–k). The thick arrows indicate the heating or cooling process. Please note the \({\bar{\Gamma }}_{100}\) point of α-Bi4I4 and the \(\bar{Z}\) point of β-Bi4I4 correspond to almost the same photoelectron emission angle. l Temperature evolution of the (100) surface gap showing a hysteresis loop.
