Exploration of Localization Phenomena at Ultra Thin Metal/ Semiconductor Interfaces: Going Beyond Surface Spectroscopies

这个新研究项目的主要目标是探索晶体半导体表面或超薄外延膜中电子局域化的基本原理。这位PI是田纳西大学的初级教员将测量表面态电导率的温度依赖性，并尝试将这些经典输运测量与态密度和带色散联系起来，这些色散是用角分辨光发射，电子能量损失光谱和扫描隧道光谱测量的。此外，我们将利用交流磁化技术探索在超高真空条件下局部磁矩的可能形成。预计这种多技术方法将最终弥合表面科学和介观物理之间的差距，从而对凝聚态物理和半导体技术产生深远的影响。这项新研究计划的主要目标是探索晶体半导体表面或超薄外延膜中电子定位的基本原理。工业部件小型化的趋势正在导致材料小到几乎是二维的。样品越小，其表面特性就越重要，因为表面代表了样品的更高百分比。为了了解表面，科学家们用电子或光子等量子粒子“轰击”表面。不幸的是，这样的实验很难与实际问题联系起来，比如电导率。在这个研究项目中，我们正在探索直接测量半导体表面和薄膜的电学和磁性质的新方法。一种新的方法正在实施，使表面与体绝缘，这样我们就可以测量表面的电阻。我们还在建造一种非常灵敏的仪器，能够探测到来自地表的极弱磁信号。预计这些新的测量将提供前所未有的见解，这将有助于弥合物理学家的原子和分子世界与工程师的设备制造世界之间的差距。＊＊＊

9705246 Weitering The primary goal of this new research program is to explore the fundamentals of electron localization at crystalline semiconductor surfaces or in ultrathin epitaxial films. The PI who is a junior faculty member at Tennessee will measure the temperature dependence of the surface state conductance and attempt to correlate these classical transport measurements with state densities and band dispersions as measured with angle-resolved photoemission, electron energy loss spectroscopy and scanning tunneling spectroscopy. In addition, we will explore the possible formation of local magnetic moments using the a.c. susceptibility technique in ultrahigh vacuum. It is expected that this multi-technique approach will ultimately bridge the gap between surface science and mesoscopic physics, thereby generating a profound impact on both condensed matter physics and semiconductor technology. %%% The primary goal of this new research program is to explore the fundamentals of electron localization at crystalline semiconductor surfaces or in ultrathin epitaxial films. The trend toward miniaturization of industrial components is leading to materials that are so small as to be nearly two-dimensional. The smaller a sample, the more important its surface properties, simply because the surface represents a higher percentage of the sample. In order to learn something about surfaces, scientists have "bombarded" surfaces with quantum particles such as electrons or photons. Unfortunately, such experiments are extremely difficult to relate to practical matters such as electrical conductance. In this research project, we are exploring new ways to measure the electrical and magnetic properties of semiconductor surfaces and thin films directly. A novel method is being implemented to electrically insulate the surface from the bulk so that we can measure the electrical resistance o f the surface. We are also constructing a very sensitive nstrument capable of detecting extremely weak magnetic signals from a surface. It is expected that these new measurements will provide unprecedented insights that will help to bridge the gap between the physicist's world of atoms and molecules and the engineer's world of device fabrication. ***