Electrical Resistance of a Point Defect

*技术摘要*与点缺陷相关的电子散射、局部化和波动最终限制了电子产品的实际应用。这项NSF项目使用材料和技术的新进展来系统地测量与一维碳纳米管导体中的单点缺陷相关的输运现象。一维限制极大地放大了单一缺陷的重要性，以至于单键或原子修饰可以显著影响两端或三端器件的特性。该项目将对通过确定性化学修饰产生的不同类型的缺陷进行比较研究，以确定可与特定化学终止有关的可重现的电子特征。变温电导光谱、扫描探头技术和噪声光谱都将被用来表征在引入单点缺陷之前和之后的器件。该项目将支持博士生的教育，并为本科生和有才华的高中生提供暑期研究机会。由于研究领域处于传统物理、化学和电气工程的十字路口，这些研究机会为科学和技术领域的职业生涯提供了出色的起点。*非技术摘要*传导大部分电流的铜线对丢失或错位的原子不是很敏感。但想象一下，当这些电线缩小到纳米级时会发生什么。当导线直径接近几个原子时，一个缺失的原子可能会产生巨大的影响。材料和科学工具的新进步使我们能够真正制造和研究这种规模的电线，以及更复杂的电子设备，如晶体管。由于实际原因，未来的电子产品更有可能使用碳线而不是铜线，所以这个项目使用中空的碳“纳米管”，即横截面只有10到20个原子的线材。通过将这些导线制成晶体管，然后逐个修改碳键，该项目将绘制并理解原子尺度设备中无序的电子后果。这项工作是一种“自下而上”的方法来理解最小规模的实用电子学，它将使未来的电子产品获得成功，因为传统的“自上而下”的制造将缩小到越来越小的规模。该项目将支持博士生的教育，并为本科生和有才华的高中生提供暑期研究机会。由于研究领域处于传统物理、化学和电气工程的十字路口，这些研究机会为科学和技术职业提供了出色的起点。

****Technical Abstract****The electronic scattering, localization, and fluctuation associated with a point defect ultimately limit what is practically achievable in electronics. This NSF project uses new advances in materials and techniques to systematically measure the transport phenomena associated with single point defects in one-dimensional, carbon nanotube conductors. The one-dimensional limit dramatically amplifies the importance of single defects, to the extent that a single bond or atom modification can substantially affect two- or three-terminal device characteristics. This project will perform a comparative study of different types of defects, produced through deterministic chemical modification, in order to identify reproducible electronic features that can be associated with specific chemical terminations. Variable temperature conductance spectroscopy, scanning probe techniques, and noise spectroscopy will all be used to characterize devices before and after the incorporation of single point defects. The project will support the education of a Ph.D. student and also provide summer research opportunities for undergraduates and talented high school students. Because the field of research lies at the crossroads between traditional physics, chemistry, and electrical engineering, these research opportunities provide outstanding starting points for careers in science and technology.****Non-Technical Abstract****The copper wires that conduct most electricity are not very sensitive to a missing or misplaced atom. But imagine what happens when these wires shrink to nanometer scales. As the wire diameter approaches a few atoms, one missing atom could have enormous effects. New advances in materials and scientific tools allow us to actually make and study wires at this scale, along with more complicated electronic devices like transistors. For practical reasons, future electronics are more likely to use carbon wires than copper ones, so this project uses hollow carbon "nanotubes," wires having a cross section of only ten to twenty atoms. By fashioning these wires into transistors and then modifying carbon bonds one by one, the project will map out and understand the electronic consequences of disorder in atomic scale devices. This work is a "bottom-up" approach to understanding practical electronics at the smallest scales, and it will inform and enable the success of future electronics as traditional, "top-down" manufacturing shrinks to ever smaller scales. The project will support the education of a Ph.D. student and also provide summer research opportunities for undergraduates and talented high school students. Because the field of research lies at the crossroads between traditional physics, chemistry, and electrical engineering, these research opportunities provide outstanding starting points for careers in science and technology.