The Josephson Effect in Ceramic Bridge at Liquid Nitrogen Temperature

Bridge junction can be made by cutting a bulk ceramic superconductor into the right sizes. Using this sort of bridge, both dc and ac Josephson effects are confirmed in liquid nitrogen . We have observed microwave induced steps at either nhf/2e or 2nhf/2e where n is an integral, as well as the oscillation of critical supercurrent with the increase of microwave power or externally applied magnetic field.