MAGNETIC FORCE MICROSCOPY AND SUPERCONDUCTORS

If the tip of an atomic force microscope is made of a magnetic material, one obtains a magnetic force microscope that can be used to sense near-surface microfields with very high resolution (10 nm has been reported). Magnetic force microscopes (MFM) have been used to map out magnetization patterns written on magnetic recording media and to study domain structures in magnetic materials. They might also be a tool to investigate magnetic properties of superconductors as I will show in this work. A possible advantage of MFM as compared to scanning tunneling microscopy is its robustness with respect to surface oxide layers etc. An example that I will consider theoretically is a domain wall in an unconventional, time-reversal breaking superconductor. I propose to use an MFM to observe the currents that flow along the wall.