Mixing at terahertz frequency band using YBa2Cu3O7-δ bicrystal Josephson junctions

Abstract

A mixing at terahertz (THz) frequency is demonstrated using YBa2Cu3O7-δ (YBCO) bicrystal Josephson junctions. Two frequency components from a slightly misaligned resonator of an far-infrared laser mixed with each other in the junction so that a Shapiro step corresponding to the intermediate frequency (IF) appears in its current-voltage curve. Up to the 490th harmonic mixing between a THz signal and a microwave local oscillator was realized with an IF signal-to-noise ratio of 9 dB.