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

Saha, K and Das, Sourin and Sengupta, K and Sen, Diptiman (2011) Spin-polarized STM spectra of Dirac electrons on the surface of a topological insulator. In: Physical Review B: Condensed Matter and Materials Physics, 84 (16).

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Abstract

We provide a theory for the tunneling conductance G(V) of Dirac electrons 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 if the in-plane rotational symmetry on the surface of the topological insulator is broken by an external field that does not couple to spin directly (such as an in-plane electric field), G(V) exhibits an unconventional dependence on the direction of the magnetization of the tip, i.e., it acquires a dependence on the azimuthal angle of the magnetization of the tip. We also show that G(V) can be used to measure the magnitude of the local out-of-plane spin orientation of the Dirac electrons on the surface. We explain the role of the Dirac electrons in this unconventional behavior and suggest experiments to test our theory.

Item Type:	Journal Article
Additional Information:	Copyright of this article belongs to The American Physical Society.
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics
Date Deposited:	23 Nov 2011 10:53
Last Modified:	23 Nov 2011 11:05
URI:	http://eprints.iisc.ernet.in/id/eprint/42281

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