Cryogen-free dilution refrigerator with 3D vector magnet for transport studies of quantum materials

具有 3D 矢量磁体的无制冷剂稀释制冷机，用于量子材料的输运研究

• 批准号: 526077868
• 金额: --
• 依托单位: Ludwig-Maximilians-Universität München (LMU)
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2023
• 资助国家: 德国
• 起止时间: 2022-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/526077868?language=en
• 关键词: Cryogen; free; dilution; refrigerator; 3D

We aim to develop the LMU‘s research endeavours on quantum materials by the acquisition of a dilution refrigerator equipped with a (9,1,1)T vector magnet. This complete apparatus will fill a critical void at the LMU where the absence of such a system hinders competitive research on quantum materials. Indeed, a dilution refrigerator permits to cool any material of interest down to 8mK with a stabiblity below 5mK. This temperature is low enough to suppress thermal fluctuations and thus to let quantum effects, stemming from electronic correlations, manifest themselves. Once in this strongly degenerate ground state, the three-dimensional vector magnet grants a complete control of the spin polarization. This allows to study in-depth a major conundrum of modern condensed matter physics: magnetic excitations and their interplay/competition with other quantum electronic phases such as superconductivity. We aim to probe these correlated phenomena by two complementary techniques, low-frequency (DC) and high-frequency (RF) electronic transport, thanks to an array of highly-filtered 48 DC and 8 RF transmission lines. High-quality filtering of the transmission lines is paramount to suppress electromagnetic heating of the electrons at low temperatures and preserve the quantum phenomenology. To complete our measurement setup, composed of pre-amplifiers and lock-in amplifiers, we wish to acquire acquire a high-definition oscilloscope and a network analyzer. Finally, we wish to buy a cryogen-free system for both simplicity of usage, as the equipement will be shared among the LMU, and long-term economy in light of the ever increasing price of liquid helium.

我们旨在通过获取配备有（9,1,1,1）T载体磁铁的稀释冰箱来开发LMU对量子材料的研究。这种完整的设备将在LMU的关键空隙中填充，因为没有这样的系统阻碍了量子材料的竞争性研究。确实，稀释冰箱允许将任何感兴趣的材料冷却至8MK，稳定性低于5MK。该温度足够低，可以抑制热波动，从而使量子效应源于电子相关性，从而表现出来。一旦处于这种强烈退化的基态，三维矢量磁铁就可以完全控制自旋极化。这允许深入研究现代冷凝物理物理学的主要难题：磁兴奋及其与其他量子电子相（例如超导性）的相互作用/竞争。我们的目标是通过两种互补技术，低频（DC）和高频（RF）电子传输来探测这些相关现象，感谢您对一系列高度过滤的48 dc和8 RF传输线。传输线的高质量滤波对于抑制低温下电子的电磁加热至关重要，并保留量子现象学。为了完成由预放大器和锁定放大器组成的测量设置，我们希望获得高清示波器和网络分析仪。最后，我们希望以简单的用途购买无低温系统，因为该设备将在LMU之间共享，并且鉴于液体氦气价格不断上涨。