Circularly Polarized Light Emission in Scanning Tunneling Microscopy of Magnetic Systems

Published

January 1, 2000

Author(s)

S Apell, David R. Penn, P Johansson

Abstract

Light is produced when a scanning tunneling microscopy is used to probe a metal surface. Recent experiments on cobalt utilizing a tungsten tip found that the light is circularly polarized; the sense of circular polarization depends on the direction of the sample magnetization, and the degree of polarization is of order 10%. This raises the possibility of constructing a magnetic microscope with very good spatial resolution. We present a theory of this effect for iron and cobalt and find a degree of polarization of order 0.1%. This is in disagreement with the experiments on cobalt as well as previous theoretical work which found order of magnitude agreement with the experimental results. However, a recent experiment on iron showed 0.0 ± 2%. We predict that the use of a silver tip would increase the degree of circular polarization for a range of photon energies.

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

61

Issue

5

Pub Type

Journals

Keywords

circularly polarized light, light emission, magnetic substrate, microscopy, scanning tunneling microscope

Citation

Apell, S. , Penn, D. and Johansson, P. (2000), Circularly Polarized Light Emission in Scanning Tunneling Microscopy of Magnetic Systems, Physical Review B (Condensed Matter and Materials Physics) (Accessed October 27, 2025)