  We address the topological nature of electronic states of step edges of
Bi(111) films by first principles band structure calculations. We confirm that
the dispersion of step edge states reflects the topological nature of
underlying films. This result unambiguously denies recent claims that the step
edge state on the surface of a bulk Bi(111) crystal or a sufficiently thick
Bi(111) films represents non-trivial edge states of the two dimensional
topologcial insulator phase expected for a very thin Bi(111) film. The trivial
step edge states have a gigantic spin splitting of one dimensional Rashba bands
and the substantial intermixing with electronic states of the bulk, which might
be exploited further.
