Ultra-low-noise Superconducting Spectrometer Technology for Astrophysics

天体物理学超低噪声超导光谱仪技术

• 批准号: ST/V000837/1
• 负责人: Stafford Withington
• 金额: $ 142.97万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FV000837%2F1
• 关键词: Ultra; low; noise; Superconducting; Spectrometer

The microwave (3 cm-3 mm), submillimetre-wave (3 mm-300 um) and far-infrared (300 um-20 um) regions of the electromagnetic spectrum contain a wealth of information about the cold dark Universe. For example, microwave radiation originating from the Big Bang can be found at the longest wavelengths, and thermal radiation coming from distant galaxies can be found at the shortest wavelengths. This part of the spectrum also contains thousands of spectral lines from numerous molecular and atomic species, which are important for studying the physics and chemistry of regions where stars and planets are being formed. It is exceptionally difficult to carry out astronomy at submillimetre wavelengths because water vapour in the Earth's atmosphere absorbs the signals that we are interested in, and observations must be made from high dry sites, or from space. The detection of submillimetre signals requires large, precision telescopes, and complex instruments must be cooled to temperatures of between 4 K and 50 mK. Because of the complexity of the instruments needed, it is not possible to buy suitable cameras, etc., and so astronomers must develop their own ultra-sensitive imaging technology. The proposed programme aims to develop a new generation of extremely sensitive detectors and receivers by fabricating microcircuits out of materials called superconductors. The superconducting state is a distinct state of matter, which has many remarkable properties. By fabricating microcircuits from certain metals and alloys (Al, Mo, Nb, Ta, Ti, TiN, NbN), and by using modern silicon micromachining techniques, it is possible to make complex electronic devices having extraordinary characteristics. For example, some of our superconducting infrared detectors could detect a domestic light bulb being turned on and off for just 1 second at a distance of 10 million miles, whilst others operate in a truly quantum mechanical way, displaying non-classical behavior, and sensitivities limited only by the Heisenberg uncertainty principle. The planned work concentrates on three specific devices: (i) Transition Edge Sensors, which operate by using the sharp transition of a superconductor to its normal state to measure the minute change in temperature that occurs when infrared power is absorbed by a tiny free-standing micro-machined membrane; (ii) Kinetic Inductance Detectors, which measure the small change in the penetration of a magnetic field into the surface of a superconductor when astronomical signals are absorbed; and (iii) Superconductor Insulator Superconductor mixers, which use extremely thin layers of superconducting and insulating material to create diodes in which quantum mechanical tunnelling occurs, and thereby operate as highly sensitive radio receivers. Each of these devices can be used singly or packed into arrays of multiple pixels to form cameras. For example, one of our projects aims to develop a millimetre-wave spectrometer, to study the highly-redshifted spectral lines of molecules such as CO, where all key parts of the spectrometer are fabricated on a single Si chip, and read out using only digital electronics. Another project aims to create an array of radio receivers for a wavelength of 0.46 mm, again all on a single silicon chip. These superconducting mixers require reference sources called local oscillators, which are extremely difficult to realise at THz frequencies. The development of local oscillator technology is therefore an essential part of our programme. The core themes of our proposed research are intrinsically intellectually fruitful, and are of central importance in enabling major areas of astronomy. At the end of the work, we will have demonstrated various new imaging technologies based on advanced superconducting devices, and the technology will then be available to construct a new generation of ultra-sensitive instruments for ground-based and space-based astronomical telescopes.

电磁波谱的微波（3 cm-3 mm）、亚毫米波（3 mm-300 um）和远红外（300 um-20 um）区域包含有关冷暗宇宙的丰富信息。例如，源自大爆炸的微波辐射可以在最长的波长下发现，而来自遥远星系的热辐射可以在最短的波长下发现。这部分光谱还包含来自众多分子和原子物种的数千条谱线，这对于研究恒星和行星形成区域的物理和化学非常重要。在亚毫米波长下进行天文学异常困难，因为地球大气中的水蒸气会吸收我们感兴趣的信号，并且必须在高干燥地点或太空进行观测。亚毫米信号的探测需要大型精密望远镜，复杂的仪器必须冷却至 4 K 至 50 mK 的温度。由于所需仪器的复杂性，无法购买合适的相机等，因此天文学家必须开发自己的超灵敏成像技术。该计划旨在通过用超导体材料制造微电路来开发新一代极其灵敏的探测器和接收器。超导态是一种独特的物质状态，具有许多显着的特性。通过用某些金属和合金（Al、Mo、Nb、Ta、Ti、TiN、NbN）制造微电路，并使用现代硅微加工技术，可以制造具有非凡特性的复杂电子设备。例如，我们的一些超导红外探测器可以在 1000 万英里的距离上检测到家用灯泡打开和关闭仅 1 秒，而其他探测器则以真正的量子力学方式运行，显示出非经典行为和灵敏度仅受海森堡测不准原理的限制。计划的工作集中在三个特定设备上：（i）过渡边缘传感器，其通过利用超导体到正常状态的急剧转变来测量当红外功率被微小独立式吸收时发生的微小温度变化。微加工膜； (ii) 动感电感探测器，用于测量当吸收天文信号时磁场渗透到超导体表面的微小变化； (iii) 超导绝缘体超导混频器，它使用极薄的超导和绝缘材料层来创建发生量子力学隧道效应的二极管，从而用作高灵敏度无线电接收器。这些设备中的每一个都可以单独使用或打包成多个像素阵列以形成相机。例如，我们的一个项目旨在开发一种毫米波光谱仪，用于研究CO等分子的高度红移谱线，其中光谱仪的所有关键部件都制造在单个硅芯片上，并且仅使用数字电子产品。另一个项目旨在创建波长为 0.46 毫米的无线电接收器阵列，同样全部位于单个硅芯片上。这些超导混频器需要称为本地振荡器的参考源，这在太赫兹频率下极难实现。因此，本地振荡器技术的开发是我们计划的重要组成部分。我们提出的研究的核心主题本质上是富有成果的，并且对于实现天文学的主要领域至关重要。工作结束后，我们将展示基于先进超导器件的各种新型成像技术，然后该技术将可用于构建新一代地基和天基天文望远镜的超灵敏仪器。

项目成果

Nonlinear mechanisms in Al and Ti superconducting travelling-wave parametric amplifiers

Al 和 Ti 超导行波参量放大器中的非线性机制

• DOI: http://dx.10.1088/1361-6463/ac782e
• 发表时间: 2022
• 期刊: Applied Physics
• 作者: Zhao S

Quantum electronics for fundamental physics

基础物理的量子电子学

• DOI: http://dx.10.1080/00107514.2023.2180179
• 发表时间: 2023
• 期刊: Contemporary Physics
• 影响因子: 2
• 作者: Withington S

Nonlinear mechanisms in Al and Ti superconducting travelling-wave parametric amplifiers

Al 和 Ti 超导行波参量放大器中的非线性机制

• DOI: http://dx.10.17863/cam.85942
• 发表时间: 2022
• 作者: Zhao S