SQUID noise thermometry for nanodevices at submillikelvin temperatures

亚毫开温度下纳米器件的 SQUID 噪声测温

• 批准号: 2460731
• 金额: --
• 依托单位: Lancaster University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2460731
• 关键词: SQUID; noise; thermometry; nanodevices; submillikelvin

In this project, the PhD student will work within the Ultra Low Temperature group to design, build and investigate Superconducting Quantum Interference Device (SQUID) based noise thermometry for nanodevices. There is a huge demand for cooling micro and nano-sized samples down to submillikelvin temperatures and ULT currently holds world record on cooling electrons in nano samples. Cooling is accomplished either by submerging nano samples in liquid helium-3 or by the direct adiabatic demagnetization of nano samples. The outstanding challenge is to measure temperature accurately, reliably and fast. Unprecedented SQUID sensitivity will permit us developing a non-contact thermometer measuring magnetic noise raising from the oscillations of the electrons in the metallic nano samples. The amount of noise is temperature-dependent and can be calculated from the first principles, which allows the thermometer to be self-calibrated. We aim to use cross-correlation between SQUID two-channels to eliminate any noise from the SQUID amplifier thus making it operational down to submillikelvin temperatures (~50 microkelvins).

在这个项目中，博士生将在超低温组工作，设计、构建和研究基于超导量子干涉器件（SQUID）的纳米器件噪声测温。将微纳米样品冷却到亚毫开尔文温度的需求非常大，而ULT目前保持着在纳米样品中冷却电子的世界纪录。冷却是通过将纳米样品浸入液态氦-3或通过纳米样品的直接绝热退磁来完成的。突出的挑战是准确、可靠和快速地测量温度。前所未有的SQUID灵敏度将使我们能够开发一种非接触式温度计，测量金属纳米样品中电子振荡引起的磁噪声。噪声的量是温度相关的，可以从第一原理计算，这使得温度计可以自我校准。我们的目标是使用SQUID双通道之间的相互关系来消除SQUID放大器的任何噪声，从而使其工作温度降低到亚毫开尔文（~50微开尔文）。