Microwave Responses of BSCCO-2212 Intrinsic Josephson Junctions at Frequencies Up to 100 GHz

Abstract

C-axis junction-stacks, with a-b plane sizes of 10 microns by 10 microns, were patterned on Bi2Sr2CaCu2O8 single crystals. We measured the current-voltage (I-V) characteristics with irradiation at a few to 100 gigahertz. At a few gigahertz and very high power level, current steps were stimulated and the voltage separations between them were independent of the microwave power. Under irradiation at 100 GHz, in addition to the suppression of critical currents, we successfully performed harmonic mixings between the 100 GHz signal and up to the 100th harmonic of a local oscillator at about 1 GHz. These experimental results show that intrinsic Josephson junctions can be good candidates for high frequency applications, and harmonic mixing may be a useful probe to investigate plasma phenomena in layered superconductors.