Effects of iron doping on the topological insulator surfaces

TL;DR

This study investigates how iron doping influences the electronic surface states of topological insulators, revealing the creation of multiple Dirac fermions and providing insights for future physics exploration and device development.

Contribution

It demonstrates the use of magnetic iron doping to modify topological insulator surfaces, showing the emergence of multiple Dirac fermions and advancing understanding of surface state manipulation.

Findings

Iron doping creates multiple Dirac fermions.

Surface electronic structure is significantly altered by magnetic perturbation.

Results guide future manipulation of topological surfaces for applications.

Abstract

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.