  Bismuth consist of bismuth bilayers that are two-dimensional topological
insulators and correspondingly, the surface is an array of edge states.
Moreover, topological models, including second order topologic order, predict
an interlayer electrical coupling mediated by hinge states. Here we report that
angle dependent magnetoresistance measurements of small diameter single-crystal
bismuth nanowires exhibit the sequence of magnetoresistance (MR) peaks at
Yamaji magic angles and a peak for B//bilayer, indicating coherent transport
between layers, and showing that the Fermi surface of surface electrons is a
warped cylinder. The MR peaks are associated with magnetic field induced flat
bands that are reminiscent of the well-known flat bands in bilayer graphene.
Coherent transport across layers is interpreted in term of transport by
topological hinge states.
