Fig. 3: Wannier obstruction in partially flat bands.
From: Quasi-localization and Wannier obstruction in partially flat bands
a, b Plot the Wannier function amplitudes of the semi-infinite zigzag graphene nanoribbon and nodal line semimetal, respectively. m and mz represent the dimer lines and layers away from the edge and surface of these two systems. n is an index of the unit cell along a translationally invariant direction. In the insets, we show that the local maxima of the Wannier functions decay algebraically. c A band dispersion of a finite-width zigzag graphene nanoribbon. The red and blue bands in the middle correspond to the edge states. d The Wannier function for the red band in (c) for various values of m. In (a), (b), and (d), the dashed curves are the guide lines showing the algebraic decay of the Wannier functions, obtained by fitting the local maxima of them.
