Detection of the spin character of Fe(001) surface states by scanning tunneling microscopy: A theoretical proposal

TL;DR

This paper proposes a theoretical method using spin-polarized scanning tunneling microscopy to identify the spin character of surface states on Fe(001), based on bias dependence influenced by magnetization orientation.

Contribution

It introduces a novel theoretical approach to determine the spin nature of surface states via bias-dependent tunneling conductance with a spin-polarized tip.

Findings

Minority-spin surface states cause strong bias dependence in conductance.

The conductance variation depends on the tip's magnetization orientation.

The method can be extended to other magnetic surfaces with surface states.

Abstract

We consider the magnetic structure on the Fe(001) surface and theoretically study the scanning tunneling spectroscopy using a spin-polarized tip (SP-STM). We show that minority-spin surface states induce a strong bias dependence of the tunneling differential conductance which largely depends on the orientation of the magnetization in the SP-STM tip relative to the easy magnetization axis in the Fe(001) surface. We propose to use this effect in order to determine the spin character of the Fe(001) surface states. This technique can be applied also to other magnetic surfaces in which surface states are observed.