Theory of a magnetic microscope with nanometer resolution
P Johansson, S Apell, David R. Penn
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.
Physical Review B (Condensed Matter and Materials Physics)
, Apell, S.
and Penn, D.
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 February 28, 2024)