Spin Transport in Fermi Liquids and Porous Media

该提案的第一部分继续了目前的一个项目：首先，将使用自旋波技术，利用核磁共振测量稀释3He-4He溶液中的自旋输运，以测试极化量子气体的新理论。在第二个实验中，人们将使用振弦式粘度计直接测量极化对动量输运的影响。此外，还将尝试创建核磁孤子，并使用核磁共振自旋扩散技术检测纯3He液体中假设的自旋波动。该提案的第二部分涉及在低温下限制在随机多孔材料中的量子液体中的效应。首先，人们将使用3He-4He解决方案，在比室温下可能的更长的长度尺度上探测随机几何图形。其次，将寻找类似于无序电子系统中所见的效应--电导波动以及随机孔隙空间内量子或自旋波干扰导致的弱和强局域化。

The first part of the proposal continues a current project: first, NMR will be used to measure spin transport in a dilute 3He-4He solution, using a spin-wave technique, in order to test a new theory for polarized quantum gases. In a second experiment, one will use a vibrating-wire viscometer to directly measure the effects of polarization upon momentum transport. In addition, attempts will be made to create nuclear magnetic solitons, and to detect hypothesized spin fluctuations in pure 3He liquid using an NMR spin-diffusion technique. The second part of the proposal deals with effects in a quantum liquid confined at low temperature in a random porous material. First, one will use a 3He-4He solution to probe random geometries over much longer length scales than is possible at room temperature. Secondly, a search will be made for effects analogous to those seen in disordered electronic systems -- conductance fluctuations and weak and strong localization resulting from quantum or spin-wave interference within the random pore space.