  Topological insulators embody a newly discovered state of matter
characterized by conducting spin-momentum locked surface states that span the
bulk band gap. So far, most of the study on topological insulator surfaces has
been limited to understanding their properties without strong Coulomb
perturbation or breaking of time reversal symmetry. We have used deposited
iron, with a large positive ionization state and significant magnetic moment as
a strong probe to modify the surface electronic structure of the Bi2Se3 surface
at the gap energy scale. We observe that such perturbation leads to the
creation of multiple Dirac fermions consistent with Z2 or Mod(2) symmetry.
Taken collectively, these results are a helpful guide in manipulating
topological surfaces for probing fundamental physics or developing device
applications.
