| タイトル | Very High Current Density Nb/AlN/Nb Tunnel Junctions for Low-Noise Submillimeter Mixers |
| 本文（外部サイト） | http://hdl.handle.net/2060/20000033613 |
| 著者（英） | Chen, Jian; Miller, David; LeDuc, Henry G.; Stern, Jeff A.; Kawamura, Jonathan; Bumble, Bruce; Zmuidzinas, Jonas |
| 著者所属（英） | California Inst. of Tech. |
| 発行日 | 2000-01-01 |
| 言語 | eng |
| 内容記述 | We have fabricated and tested submillimeter-wave superconductor-insulator-superconductor (SIS) mixers using very high current density Nb/AlN/Nb tunnel junctions (J(sub c) approximately equal 30 kA/sq cm) . The junctions have low resistance-area products (R(sub N)A approximately 5.6 Omega.sq micron), good subgap to normal resistance ratios R(sub sg)/R(sub N) approximately equal 10, and good run-to-run reproducibility. From Fourier transform spectrometer measurements, we infer that omega.R(sub N)C = 1 at 270 GHz. This is a factor of 2.5 improvement over what is generally available with Nb/AlO(x)/Nb junctions suitable for low-noise mixers. The AlN-barrier junctions are indeed capable of low-noise operation: we measure an uncorrected receiver noise temperature of T(sub RX) = 110 K (DSB) at 533 GHz for an unoptimized device. In addition to providing wider bandwidth operation at lower frequencies, the AlN-barrier junctions will considerably improve the performance of THz SIS mixers by reducing RF loss in the tuning circuits. |
| NASA分類 | Electronics and Electrical Engineering |
| レポートNO | Rept-2000-5 |
| 権利 | No Copyright |
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