Development of a Terahertz detector Array based on superconducting tunnel junctions coupled to a thin superconductor film

研究了一种利用超导隧道结与大尺寸太赫兹吸收超导薄膜耦合的太赫兹探测器。我们还提出了一种新的太赫兹探测器的设计与传输线STJ。后一种探测器具有集成在对数周期天线的两翼上的两个长结。在这种类型中，长结是基于库珀对破坏过程工作的高损耗传输线，其中结的长度和宽度分别决定吸收效率和频率带宽。制作了Nb/Al/AlOx/Al/Nb结探测器，验证了探测器的工作原理。我们已经检测到太赫兹辐射的基础上的库珀对断裂（CPB），并确认，灵敏度有一个逐渐增加，从0.35太赫兹，一个值，对应于Nb/Al双层的有效间隙频率。我们还确定了第三个四分之一波长共振及其谐波信号的光子辅助隧穿（PAT）过程中工作。STJ检测器具有两种检测过程都可用的新功能。该功能将允许探测器应用于未来的THz成像，具有宽的频率选择性。

A terahertz detector using a superconducting tunnel junction (STJ) coupled to a large terahertz-absorbing superconductor film was investigated. We also proposed a design of a new terahertz detector with transmission-line STJs. The latter detector has two long junctions integrated on both wings of a log-periodic antenna. In this type, the long junction is a high-loss transmission-line working based on the Cooper-pair breaking process, in which the junction length and width determine the absorption efficiency and frequency bandwidth, respectively. A detector using Nb/Al/A1Ox/Al/Nb junctions was fabricated, and the principle of the detector was verified. We have detected terahertz radiation based on the Cooper-pair breaking (CPB), and confirmed that the sensitivity has a gradual increase from 0.35 THz, a value that corresponds to the effective gap frequency of the Nb/Al bilayer. We have also identified the third quarter-wavelength resonance and its harmonic signals working on the photon-assisted tunneling (PAT) process. The STJ detector has the new functionality that both detection processes are available. This functionality will allow the detector to be applied in future THz imaging with wide frequency selectivity.