To understand the MIRO and ZRS better and confirm the domain formation
of current distribution on 2DEG under microwave radiation, a good way
is to image the current distribution directly. To accomplish this job,
we will measure the magnetic field produced by the current distribution
and rebuild the current distribution from this magnetic field profile.

To rebuild the current distribution from the magnetic field profile
doesn’t have unique solution in 3D case. However, if the current
is restricted to 2D, the problem can be solved uniquely. B. J. Roth *et al* [J. Appl. Phys. **65**,
361 (1988)] developed a mathematical algorithm based on the Fourier
transform technique to obtain the 2D current distribution from measured
perpendicular component of the magnetic field.

To measure the
perpendicular component of the magnetic field, we will use the Scanning
Hall Probe Microscope (SHPM). The basic principle of SHPM is the STM
technique, but instead of using tunneling tips, SHPM uses a small Hall
bar as a scanning probe. When magnetic field acts on the Hall probe, a
Hall voltage will be produced by the magnetic field. According to the
classical Hall effect, this Hall voltage is proportional to magnetic
field perpendicular to the Hall probe surface. Hence, by measuring this
Hall voltage, the SHPM can image the profile of the perpendicular
component of the magnetic field. For more details of SHPM, please check
the website:

http://www.nanomagnetics-inst.com