Mixing and detection in YBaCuO step-edge Josephson junction arrays up to 670 GHz

Submillimeter wave detectors and mixers based on YBa/sub 2/Cu/sub 3/O/sub 7/ (YBCO) step-edge Josephson junctions incorporated into planar antennas were designed and tested up to 670 GHz at temperatures from 12 to 65 K. A quasi-optic coupling system with a LaAlO/sub 3/ lens was used. In some samples the noise intrinsic in the detection process does not follow the Johnson noise law but has a minimum, which for a given sample may occur in the temperature range between 35 to 50 K. Harmonic mixing recorded at 670 GHz proves that the system equilibrium is established in a time shorter than 500 fs.<
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