Low Temperature Scanning Tunneling Microscopy

w：\awards\awards96\*.doc 9623448 DeLozanne 这个凝聚态物理项目将继续发展 低温超高真空扫描隧道显微镜（STM）。STM用于高Tc材料的原位裂解。 清洁表面的初步STM研究揭示了新的结构特征和YBCO材料中的可重复间隙。 结构特征的起源 不确定，将在本项目中进一步研究。 仪器的性能将得到改进，以允许更低的基本工作温度和更低的噪声。 这将扩大可以研究的超导材料的范围。 特别感兴趣的是超导体中的涡旋结构和电荷密度波的测量。这是一个根本性的项目。 这一结果对超导理论、 并可能导致 到 发展 的 新型超导材料 本项目将继续开发具有独特功能的表面结构测定工具-扫描隧道显微镜（STM）。利用该仪器，可以将高Tc超导体的小单晶冷却到非常低的温度（20 K），切割晶体，并在低温下用STM研究表面结构。 初步数据显示，在高Tc材料的起源是不确定的，但肯定有关的机制，高Tc超导不寻常的结构特征。该项目将阐明几种高温材料的结构特性的本质，并将研究这种现象的温度依赖性。该仪器将进一步发展，以允许更低的基础温度，这将增加可以研究的超导材料的范围。 这是凝聚态物理学中的一个基础项目。这些结果对超导理论的发展具有重要意义，并可能导致新的超导材料的发展。 ***

w:\awards\awards96\*.doc 9623448 DeLozanne This condensed matter physics project will continue development of a low-temperature, ultra-high-vacuum, scanning tunneling microscope (STM). The STM is used for in-situ cleavage of high-Tc materials. Preliminary STM study of the clean surfaces has revealed novel structural features and an reproducible gap in YBCO materials. The origin of the structural features is uncertain and will be further investigated in this project. The instrument capabilities will be improved to allow a lower base operating temperature, and lower noise. This will expand the range superconducting materials that can be investigated. Of particular interest are measurement of vortex structure and charge density waves in superconductors. This is a fundamental project. The results will be of significance for theories of superconductivity, and may lead to development of new superconducting materials. %%% This project will continue development of a surface structure determination tool, a scanning tunneling microscope (STM), which has unique capabilities. With this instrument it is possible to take a small single crystal of a high-Tc superconductor, cool it to very low temperatures (20 K), cleave the crystal, and study the surface structure with the STM at the low temperature. Preliminary data have revealed unusual structural features in high-Tc materials whose origin is uncertain, but which certainly relevant to mechanisms of high-Tc superconductivity. This project will clarify the nature of the structural properties of several high-Tc materials, and will study the temperature dependence of the phenomena. The instrument will be further developed to allow a lower base temperature, which will increase the range of superconducting materials that can be investigated. This is a fundamental project in condensed matter physics. The results will be of significance for theories of superconductivity, and may lead to development of new superconducting materials. ***