On-Chip milliKelvin Electronic Refrigerator for Astronomical and Quantum Device Applications

我们打算开发一种用户友好的新技术，使小型设备能够冷却到极低的温度(&lt；100mk)。这样的能力将使多样化和未来主义的应用程序蓬勃发展。这些领域包括黑洞探测、癌症探测和量子计算。我们建议通过使用电子冷却过程来实现这一点，在电子冷却过程中，相对高能(热)的载流子(电子或空穴)通过量子力学隧道离开介质，从而导致介质中的平均电子温度降低。应用这种工艺来实现极低的温度是非常新的，我们希望通过将新一代半导体SiGe引入电子冷却器的设计中，以及完善的硅加工技术来极大地提高其效率-这样，最终可以经济地生产出符合工业标准的冷却器。冷却器将在一个小型硅芯片的外围制造，该芯片与安装在芯片中心的有源设备(有效载荷)有热连接。这需要非常好的热设计，以便电子冷却器有效地冷却有效载荷。然而，在某些情况下，只需要冷却电子/不需要冷却晶格原子；在这里，SiGe在控制电子和晶格之间的热耦合方面提供了很大的灵活性。这种电子制冷器可以从0.3K的起始温度开始运行，这可以由一个无低温流体的闭合循环氦低温恒温器产生，因此可以设想一种能够进入~10mK工作环境的转向开关技术。这将是一个巨大的技术进步，因为现有技术需要大量复杂的基于低温流体的设备。在项目的第一阶段，我们将研究几种实现有效电子冷却的方法，利用SiGe及其相关金属硅化物在极低温度下可以获得的广泛基本电子条件/从而增强载流子传输和热电效应。然后，新的冷却器将在两个备受关注的领域进行测试，即辐射探测器和量子信息设备。例如，它们可以极大地增强我们探测最早黑洞发出的光子的能力，卫星探测器的工作温度为100mk。而且，非常重要的是，这种检测器可以彻底改变在生物医学研究中广泛使用的荧光检测，使我们能够在理解基于基因的疾病(例如癌症)和单个细胞的工作原理方面取得进展。此外，量子计算时代需要运行在10-20mK的量子比特设备，开辟的计算前景确实令人敬畏。华威正在协调该项目，并召集了一个由科学家和工程师组成的紧密联盟，他们来自四所英国大学-华威、卡迪夫、莱斯特和伦敦(Royal Holloway)-以及四家尖端公司，他们拥有适当的专业知识，致力于这项技术的开发，并在两个关键领域展示其适用性和优势。我们还与欧洲领先的MK冷却器中心(赫尔辛基理工大学)密切合作。英国处于非常有利的地位，可以从这项真正令人兴奋的新技术中受益，这个项目将为其实现播下种子。

We intend to develop a new user-friendly technology that would enable small devices to be cooled to exceedingly low temperatures (<100mk). Such a capability will allow diverse and futuristic applications to flourish. These include the detection of black holes, cancer detection and quantum computing. We propose to do this by using an electronic cooling process where relatively energetic (hot) carriers (electrons or holes) quantum mechanically tunnel out of a medium, thereby causing the average electronic temperature in the medium to decrease. The application of this process to realise extremely low temperatures is very new, and we want to greatly improve its efficiency by introducing a new generation semiconductor SiGe into the design of the electronic cooler and, along with it, the well developed silicon processing techniques - so that, ultimately, such coolers can be produced economically and to industrial standards. Coolers will be fabricated around the periphery of a small silicon chip with thermal links to the active device ( payload ) mounted in the centre of the chip. This requires very good thermal design such that the electronic cooler efficiently cools the payload. However, in some cases, it is only necessary to cool the electrons / not the lattice atoms; here SiGe gives a lot of flexibility in controlling the thermal coupling between the electrons and the lattice. Such electronic coolers can operate from a starting temperature of 0.3K, which can be produced by a cryogenic fluid-free closed-cycle helium cryostat, so that a turn-switch technology can be envisaged enabling access to ~10mK working environments. This will be a huge technology step forward, as existing techniques require massive and complex cryogenic fluid-based equipment.During the first phase of the project we will examine several approaches to the realisation of effective electronic cooling, exploiting the wide range of fundamental electronic conditions that can be obtained at very low temperatures in SiGe with its associated metal silicides / thereby enhancing carrier transport and thermoelectric effects. The new coolers will then be tested in two areas of great topical interest, namely radiation detectors and quantum information devices. They could dramatically enhance our ability to detect, for example, the photons that emanate from the earliest black holes, with satellite-based detectors operating at <100mK. And, very significantly, such detectors could revolutionize the fluorescence light detection that is used extensively in biomedical research, enabling advances in our understanding of genetically-based diseases (e.g. cancer) and the workings of a single cell. Furthermore, the computational vista that is opened-up by the quantum computing era requiring qubit devices operating at 10-20mK, is truly awe inspiring. Warwick is co-ordinating the project and has assembled a tightly knit consortium of scientists and engineers with appropriate expertise from four UK universities -Warwick, Cardiff, Leicester and London(Royal Holloway) - and four leading-edge companies, concerned with the development of this technology and the demonstration of its applicability and advantages in two key areas. We are also working closely with Europe's leading centre on mK coolers (Helsinki University of Technology). The UK is exceedingly well positioned to derive benefit from this genuinely new and exciting technology, and this project will sow the seeds for its realisation.