Noise Investigations of Condensed Matter Systems

大多数材料在各种电、机械、磁和光学参数中表现出缓慢的波动，具有广泛的特征率分布。尽管这种波动频谱的简单形式（1/f）无处不在，但正如过去的实验所证明的那样，涉及各种各样的机制。这些波动之所以引起人们的兴趣，主要有两个原因。首先，它们限制了各种传感器和设备的性能。其次，它们提供了一种有用的工具来研究材料的基本性质，特别是那些鲜为人知的材料，如玻璃，它们表现出部分冻结的随机结构。他们使用电学、光学和磁波动技术来研究普通玻璃、玻璃金属、自旋玻璃、具有随机域结构的磁性材料和其他系统。他们特别关注的是随着温度的降低，流体随机结构如何从冻结随机结构中出现，以及在非常低的温度下保持哪种类型的非冻结模式。

Most materials exhibit slow fluctuations, with a broad distribution of characteristic rates, in a variety of electrical, mechanical, magnetic, and optical parameters. Despite the ubiquity of a simple form (1/f) for the frequency spectrum of such fluctuations, a wide variety of mechanisms are involved, as has been demonstrated in past experiments. These fluctuations are of interest for two general reasons. First, they limit the performance of a variety of sensors and devices. Second, they provide a useful tool to study fundamental properties of materials, especially the poorly understood types of materials known as glasses, which exhibit partially frozen random structures. They are using electrical, optical and magnetic fluctuation techniques to investigate ordinary glasses, glassy metals, spin glasses, magnetic materials with random domain structures, and other systems. Their particular focus is on how frozen random structures emerge from fluid random structures as temperature is lowered, and on what type of unfrozen modes remain at very low temperatures.