A grain boundary Josephson junction as a mixer to evaluate terahertz emission from intrinsic Josephson junctions

摘要

To evaluate terahertz emission from intrinsic Josephson junctions, we used a YBaCuO (YBCO) grain boundary Josephson junction as a terahertz detector. Shapiro steps have been clearly seen on the current-voltage curves of the YBCO junction irradiated with the emission from either a VDI-Tx-S140 transmitter (tens of μW at 620 GHz) or a BiSrCaCuO stack (25 μW at 500 GHz). While the harmonic mixing has been successfully performed with the VDI transmitter as the signal source, the evaluation of the intrinsic Josephson junctions is still undergoing.