Magnetic field profiles of a superconducting strip in an oblique magnetic field

We consider the critical state of a thin superconducting strip in an oblique applied magnetic field Ha without any restrictions on the dependence of the critical current density jc on the local magnetic induction B. In such a strip, jc in general is not constant across the thickness of the sample and differs from Jc/d, where Jc is the critical sheet current. It is shown that in the case of B-dependent jc, the profiles Hz(x) of the magnetic-field component perpendicular to the strip plane generally depend on the in-plane component Hax of the applied magnetic field Ha. On the basis of this analysis, we explain how one can extract jc(B) from the magnetic-field profiles Hz(x) measured by magneto-optical imaging at the upper surface of the strip.