On-chip spectroscopic detection of terahertz radiation emitted from a quasiparticle-injected nonequilibrium superconductor using a high-Tc Josephson junction

We report a novel sensitive terahertz spectroscopy in which both the electromagnetic generator and the detector are fabricated on the same chip. The radiation emitted from a tunnel-injected nonequilibrium high temperature (high-Tc) YBa2Cu3O7−y superconductor is detected by a high-Tc bicrystal Josephson junction. The observed data are converted to the spectral data by means of inverse Hilbert transformation. The resultant emitted spectra exhibit a broad peak around 1 THz, extending up to 2.5 THz. The relation to the Josephson plasma emission is discussed.