We fabricated Nb/AlOx/Nb Josephson junctions on Bi2Sr2CaCu2O8+δ (BSCCO) single crystals to detect the Josephson plasma in BSCCO. A thin gold layer was employed between BSCCO and Nb/AlOx/Nb to avoid interdiffusion of oxygen in BSCCO. We measured the current-voltage properties of the Nb/AlOx/Nb junctions in a liquid helium bath, and observed clear periodic step structures. A characteristic frequency corresponding to the voltage spacing of the steps was 63 GHz, which agreed with the Josephson plasma frequency of BSCCO. The result indicates that the Josephson plasma in BSCCO can interact with the ac Josephson current of the closely coupled Nb/AlOx/Nb Josephson junctions.
ASJC Scopus subject areas
- Condensed Matter Physics