Low-noise 0.5THz all-NbN superconductor-insulator-superconductor mixer for submillimeter wave astronomy

• DOI: 10.1063/1.2940235
• Publication Date: 2008-06-04T23:17:22Z
• Authors: Jing Li; Masanori Takeda; Zhen Wang; Sheng-Cai Shi; Ji Yang
• Keywords: Noise temperature

We report the detection of spectral line emission from CO (J=4–3) at 0.46THz using a low-noise 0.5THz superconductor-insulator-superconductor (SIS) mixer incorporating NbN∕AlN∕NbN tunnel junctions (with an energy gap 5.6meV) and NbN∕MgO∕NbN tuning circuit, which is installed on 30cm submillimeter telescope. Uncorrected receiver noise temperatures as low 149K are measured telescope 0.45–0.50THz for unoptimized device. Moreover, all-NbN SIS exhibits high stability in considerably large dc bias range significantly compared with Nb mixer.