Experimental Studies at Ultralow Temperatures

9623716博兹勒这个项目是在超低温下对三种不同的材料进行研究，同时开发先进的DC SQUID放大器来支持这项工作。第一个研究是超流3He的磁性质，重点是SQUID和核磁共振静态磁化率测量之间的差异。第二个研究是关于3He薄膜在足够小的磁场中可以表现出二维的核铁磁相变。在这些磁场中，常规的核磁共振技术是不能使用的。最后，我们将研究降维系统中的电导，包括由有效的一维导线组成的人工二维网络中的无序物理。这个项目是对超低温材料的研究，结合并支持超低温实验技术的发展，包括先进的低噪声放大器。在接近1mK(绝对零度以上0.001度)的温度下，氦的稀有同位素(氦-3)转变为超流体，其磁性尚不清楚。这些磁性将在本项目中进行研究。液态氦-3薄膜也将被研究，因为它们已被证明是二维磁性的极好模型。人工一维和二维金属系统将被制造和研究，以更好地了解无序在自然物理系统中的作用。***

9623716 Bozler This project is an investigation of three different materials at ultralow temperatures while developing advanced dc SQUID amplifiers to support this work. The first study is of the magnetic properties of superfluid 3He, focusing on the discrepancy between SQUID and NMR measurements of the static susceptibility. The second study is of thin films of 3He in magnetic fields sufficiently small that a wo-dimensional nuclear ferromagnetic transition can be manifested. In these magnetic fields, conventional NMR techniques are unusable. Finally, electrical conduction in reduced dimensionality systems will be studied, including the physics of disorder in artificial two-dimensional networks of effectively one-dimensional wires. %%% This project is a study of materials at ultralow temperatures combined with, and supported by, the development of ultralow temperature experimental techniques, including advanced low-noise amplifiers. At temperatures near 1 mK (0.001 degrees above Absolute Zero) the rare isotope of helium (helium-3) changes to a superfluid whose magnetic properties are not yet well understood. These magnetic properties will be studied in this project. Thin films of liquid helium-3 will also be studied because they have proved to be an excellent model for magnetism in two dimensions. Artificial one- and two-dimensional metallic systems will be manufactured and studied to better understand the role of disorder in natural physical systems. ***