Fig. 6
From: Topological characterizations of an extended Su–Schrieffer–Heeger model
Detection method. a shows the absorption image of atoms with 20-ms free expansion. Atoms in different momentum states occupy different positions after this time-of-flight expansion. These components are very well separated. b shows the multi-Gaussian fitting. Each column of the image shown in a is summed, and the size of each Gaussian function is set to be equal. As such, the peak values for each column of the fit orders are proportional to the atom numbers belonging to the different momentum orders
