  The electrical transport properties of corner-shaped Al superconducting
microstrips have been investigated. We demonstrate that the sharp turns lead to
asymmetric vortex dynamics, allowing for easier penetration from the inner
concave angle than from the outer convex angle. This effect is evidenced by a
strong rectification of the voltage signal otherwise absent in straight
superconducting strips. At low magnetic fields, an enhancement of the critical
current with increasing magnetic field is observed for a particular combination
of field and current polarity, confirming a recently theoretically predicted
competing interplay of superconducting screening currents and applied currents
at the inner side of the turn.

Superconductivity