Theory of a magnetic microscope with nanometer resolution

Published

January 1, 2001

Author(s)

P Johansson, S Apell, David R. Penn

Abstract

We propose a theory for a type of apertureless scanning near field microscopy that is intended to allow the measurement of magnetism on a nanometer length scale. A scanning tunneling microscope (STM) is used to scan a magnetic substrate while a laser is focused on the STM tip. The electric field between the tip and substrate is enhanced in such a way that the magnetic Kerr effect, which is normally of order 0.1%, is increased by up to two orders of magnitude for the case of a Ag or W tip and an Fe sample. Apart from this there is also a large background of circular polarization which is non-magnetic in origin. This circular polarization is produced by light scattered from the STM tip and substrate. A detailed retarded calculation for this light-in-light-out experiment is presented.

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

64

Issue

5

Pub Type

Journals

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Keywords

Kerr effect, laser, microscope, nanometer resolution, near field microscopy, STM

Citation

Johansson, P. , Apell, S. and Penn, D. (2001), Theory of a magnetic microscope with nanometer resolution, Physical Review B (Condensed Matter and Materials Physics), [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=620537 (Accessed October 18, 2025)