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

我们的目标是通过收购配备有（9，1，1）T矢量磁体的稀释制冷机来发展LMU在量子材料方面的研究工作。这个完整的装置将填补LMU的一个关键空白，因为缺乏这样的系统阻碍了量子材料的竞争性研究。事实上，稀释制冷机允许将任何感兴趣的材料冷却到8 mK，稳定性低于5 mK。这个温度足够低，可以抑制热涨落，从而让源于电子关联的量子效应显现出来。一旦处于这种强简并基态，三维矢量磁体赠款完全控制自旋极化。这允许深入研究现代凝聚态物理学的一个主要难题：磁激发及其与其他量子电子相（如超导性）的相互作用/竞争。我们的目标是通过两种互补的技术，低频（DC）和高频（RF）电子传输，探测这些相关的现象，这要归功于高度过滤的48个DC和8个RF传输线阵列。传输线的高质量滤波对于抑制低温下电子的电磁加热和保持量子现象至关重要。为了完成由前置放大器和锁定放大器组成的测量设置，我们希望获得一台高清示波器和一台网络分析仪。最后，我们希望购买一个无冷冻剂的系统，既方便使用，因为设备将在LMU之间共享，又考虑到液氦价格不断上涨的长期经济性。

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.