Low Temperature Scanning Probe Microscopy

低温扫描探针显微镜

• 批准号: 0072834
• 负责人: Alex de Lozanne
• 金额: $ 22.5万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0072834&HistoricalAwards=false
• 关键词: Low; Temperature; Scanning; Probe; Microscopy

In this project a two-tip scanning tunneling microscope (STM) of a new design, never considered before, will be developed. In this design the two tips probe a very thin sample from opposite sides. In addition, another two-tip STM will be designed in which the two tips probe the sample in a more conventional geometry, with both tips on the same side of the sample. Nanotube tips recently developed by the investigator enable these designs. Nanotube tips may be ideal for spin-polarized tunneling, as well as for a host of scientific and practical applications that can benefit from a coherent point source of spin-polarized electrons. The two-tip STM will make possible new experiments that will probe the Green function of the sample material, so that one can get detailed information on semiconducting or metallic samples such as mean free path, the phase and energy dependence of scattering from impurities, details of the band structure, and the transition from the ballistic to diffusive transport. This instrument can also probe the symmetry of the order parameter in a superconductor, so that refinements of the current d-wave picture can be obtained for high temperature superconductivity. Graduate and undergraduate students will participate in this project. They will benefit from training in advanced instrumentation and techniques, in the development of the novel STM instrument, and from using it to probe the behavior of electrons in the most detailed fashion yet available.%%%Microscopes with ever increasing ability to probe small details have been major instruments in advancing our understanding of the microscopic structures and behaviors of materials. Scanning tunneling microscopes (STMs) are the latest types of such instruments that now allow the probing of materials at the atomic level of dimensions. In this project, a new type of STM, based on the use of two, rather than one, probe tips will be developed. One version will have the two tips on opposite sides of a very thin sample, a geometry that has never before been even contemplated. A second version of the two-tip STM will be of a more conventional geometry, in which the two tips are on the same side of the sample. Both versions can be realized on the basis of probe tips, which are atomically sharp needles (carbon nanotubes), that were recently developed in the investigator's laboratory. Such two-tip STMs will allow a new set of investigations of the properties of materials, including high temperature superconducting compounds that will result in a better understanding of their structure and behavior. These results will ultimately be of use and benefit to technology. This project will involve the participation of graduate and undergraduate students. They will thereby acquire knowledge and skills in a very active contemporary area of condensed matter physics and materials science. These will enable them to be productive members of the scientific/technological workforce of the next few decades of this century.***

在该项目中，将开发出一种新设计的两尖扫描隧道显微镜（STM），从未考虑过。 在此设计中，这两个尖端从相对侧探测了非常薄的样品。 此外，将设计另一个两尖的STM，其中两个尖端在更常规的几何形状中探测样品，两个尖端在样品的同一侧。 研究人员最近开发的纳米管技巧可以实现这些设计。 纳米管尖端可能是自旋偏振隧道的理想选择，以及许多科学和实用的应用，这些应用可以从旋转偏振电子的连贯点源中受益。 两尖的STM将使可能探测样品材料的绿色功能的新实验，从而可以获取有关半导体或金属样品的详细信息，例如平均自由路径，杂质散射的相位和能量依赖性，从杂质结构的细节，以及从弹道传输到扩散运输的过渡。 该仪器还可以在超导体中探测顺序参数的对称性，因此可以获得当前D-Wave图片的改进以获得高温超导性。 研究生和本科生将参加该项目。 它们将受益于高级仪器和技术的培训，新颖的STM仪器的开发，以及使用它以最详细的方式探测电子的行为。%% %%显微镜具有越来越多的探索小细节的能力，这是我们对材料的微观结构和行为的理解的促进的主要工具。 扫描隧道显微镜（STM）是此类仪器的最新类型，现在允许在原子层的原子水平上探测材料。 在这个项目中，将开发一种新型的STM，基于两个而不是一种使用探针提示。 一个版本将在一个非常薄的样品的相对侧面有两个技巧，这是从未考虑过的几何形状。 两尖的STM的第二个版本将是更传统的几何形状，其中两个尖端在样本的同一侧。 这两个版本都可以根据探针尖端（碳纳米管（碳纳米管），这些探针尖端是在研究者的实验室中开发的。这种两尖的STM将允许对材料的性质进行新的研究，包括高温超导化合物，从而更好地了解其结构和行为。 这些结果最终将有利于技术。 该项目将涉及研究生和本科生的参与。 他们将在非常活跃的当代物理和材料科学领域中获得知识和技能。这些将使他们成为本世纪未来几十年的科学/技术劳动力的生产成员。***