Disorder and Correlations in Novel Low Dimensional Systems

该项目研究超薄、低原子质量、金属薄膜和金属线的电子特性。这项工作对广泛研究量子输运现象中无序、相关性和维度的作用的凝聚态物质群体很有兴趣。该项目侧重于两个领域。首先是薄膜超导体的平行磁场研究，其中磁场与电子自旋的耦合使系统通过一阶相变进入正常状态。与这种转变相关的是一些新颖的、尚未被理解的非平衡行为，如雪崩、状态记忆和重入。这部分项目的目标是更充分地研究无序和维度对非平衡行为的作用，并寻找状态记忆效应的可能应用。第二个研究领域涉及高阻金属薄膜的磁输运和态密度测量。最终目标是对二维系统中的库仑隙（Efros-Shklovskii隙）进行首次测量，然后将隙行为与观测到的绝缘相磁输运行为联系起来。超薄、均匀无序的Be薄膜将用于这些研究。这些项目为培养本科生、研究生和博士后提供了良好的机会。事实上，这项研究弥合了深奥的量子物理学和更以技术为导向的材料科学之间的差距。本研究项目研究超薄、低原子质量、金属薄膜和金属线在极端环境下的电子特性。由于该项目既涉及样品的制作，也涉及对这些样品的测量，因此它为学生和博士后提供了不同寻常的广泛的教育和研究机会。将进行两个项目：一个涉及在非常高的平行（与薄膜表面）磁场下薄膜超导性的行为。这种转变本质上是量子的，并表现出不寻常的准静态非平衡行为，如雪崩和记忆效应。这些效应的微观起源尚不清楚，但预计会影响量子相变的一般领域。另一个问题是电子-电子相互作用在非常高电阻Be薄膜的电子传递特性中的作用。人们相信，Be薄膜的非颗粒特性将使我们在这个非常重要的问题上取得进展，这个问题现在被认为与各种各样的凝聚态问题有关

9972151AdamsThe project investigates the electronic properties of ultra-thin, low atomic mass, metal films and wires. This work is of interest to a widespread condensed matter community studying the roles of disorder, correlations, and dimensionality in quantum transport phenomena. The project is focused on two areas. The first is parallel magnetic field studies of thin film superconductors where coupling of the magnetic field to the electronic spins drives the system into the normal state via a first-order phase transition. Associated with this transition are some novel and as of yet poorly understood non-equilibrium behavior such as avalanches, state memory and reentrance. The goal of this part of the project is to more fully investigate the roles of disorder and dimensionality on the non-equilibrium behavior and to look for possible applications of the state memory effect. The second area of study involves magneto-transport and density of states measurements of very high resistance metal films. The ultimate goal is to make the first measurements of the Coulomb gap (Efros-Shklovskii gap) in a 2D system and then correlate the gap behavior with the observed magneto-transport behavior in the insulating phase. Ultra-thin, homogeneously disordered Be films will be used for these studies. These projects afford excellent opportunities for training of undergraduate students, graduate students, and post-docs. This research, in fact, bridges a gap between esoteric quantum physics and more technologically oriented material science.%%%This research project investigates the electronic properties of ultra-thin, low atomic mass, metal films and wires in extreme environments. Since the project involves both the fabrication of samples and measurements on those samples, it offers unusually broad educational and research opportunities for students and post-docs. Two projects will be pursued: One involves the behavior of thin film superconductivity in very high parallel (to the film surface) magnetic fields. This transition is fundamentally quantum in nature and displays unusual quasi-static non-equilibrium behavior such as avalanches and memory effects. The microscopic origin of these effects is still not understood but is expected to impact the general field of quantum phase transitions. The other concerns the role of electron-electron interactions in the electron transport properties of very high resistance Be films. It is believed that the non-granular character of the Be films will allow progress to be made on this very important problem that is now known to be relevant to a wide variety of condensed matter problems.***