Spin polarized STM spectra of Dirac Fermions on the surface of a topological insulator

Abstract

We provide a theory for the tunneling conductance $G(V)$ of Dirac Fermions on the surface of a topological insulator as measured by a spin-polarized scanning tunneling microscope tip for low bias voltages $V$. We show that $G(V)$ exhibits an unconventional dependence on the direction of magnetization of the tip and can be used to measure the magnitude of the local out-of-plane spin orientation of the Dirac Fermions on the surface. We also demonstrate that if the in-plane rotational symmetry on the surface of the topological insulator is broken by an external field, then $G(V)$ acquires a dependence on the azimuthal angle of the magnetization of the tip. We explain the role of the Dirac Fermions in this unconventional behavior and suggest experiments to test our theory.

7 pages, 5 Figs

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Cited by in corpus (9)

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• Magnetic field induced Fabry-Pérot resonances in helical edge states
• Edge states of a three-dimensional topological insulator
• Spin injection into a metal from a topological insulator
• Transport across a junction of topological insulators and a superconductor
• Confining electrons on a topological insulator surface using potentials and a magnetic field
• Tunnel Magnetoresistance scan of a pristine three-dimensional topological insulator
• Transport and STM studies of hyperbolic surface states of topological insulators
• Probing surface states exposed by crystal terminations at arbitrary orientations of three-dimensional topological insulators