Extended Data Fig. 1: Phase bands of discrete-time quantum walks.
From: Simulation of a Floquet non-Abelian topological insulator with photonic quantum walks
A case with Q = J, corresponding to phase-band singularities satisfying \(J=\widetilde{k}\widetilde{i}\). Inset: locations of the Dirac points with quaternion charges in the (k, t) space. P denotes the base point for the encircling paths.
