Fig. 4: The Chern number and C4z eigenvalues of occupied states as a function of kz.
From: Double Majorana vortex flat bands in the topological Dirac superconductor
a The illustration of the base space of target system \({\widetilde{{{\mathcal{H}}}}}_{\pm }({{\bf{k}}};\theta ,{k}_{z},r)\). Each point on the circle labeled by θ is a subsystem that is macroscopically small but microscopically large. b The Chern number of \({{{\mathcal{H}}}}_{\pm }({{\bf{k}}};{k}_{z})\) as a function of kz. D1,2 represents the momentum at which the BdG Dirac point appears. c The energy spectrum of \({{{\mathcal{H}}}}_{{{\rm{BdG}}}}(0,0,{k}_{z})\) with the C4z eigenvalues. d The gapped energy spectrum of \({{{\mathcal{H}}}}_{{{\rm{BdG}}}}(\pi ,0,{k}_{z})\) (black lines) with the C4z eigenvalues, and \({{{\mathcal{H}}}}_{{{\rm{BdG}}}}(\pi ,\pi ,{k}_{z})\) (gray lines) with the C2z eigenvalues as a function of kz. The solid lines and dashed lines represent electron-like states and hole-like states, respectively. All parameters are same as that for Fig. 2. All labeled angular momenta correspond to negative energy bands.
