Superconductor Magneto-optics and Theory

Some remarks are made on how to determine by magneto-optical imaging the electric currents flowing in a superconductor. The inversion problem is discussed how to compute these currents from the magnetic field measured in a planar magneto-optical indicator film positioned close to the conductor. Next, some geometries are listed for which the currents and magnetic fields can be computed from first principles for given constitutive laws of the superconductor. Finally, an example is given how novel current loops appear in a thin flat superconductor during the application of a large dc field and weak in-plane ac field that causes the critical currents to relax anisotropically.