Phase slips in mesoscopic superconducting triangles

Voltage–current (V(I)) characteristics are investigated in the superconducting state of an equilateral triangle of 2.2 μm2 area. Several steps in the V(I) curves indicate the presence of phase slip centers in the triangle. The field dependence of these steps follows the Little-Parks oscillations of the phase boundary, associated with the change of vorticity. The influence of the contacts manifests itself as an excess voltage and a negative differential resistance. In addition we show that the position of the current contacts modify the superconducting phase boundary measurements.