Quasi-1-D Molecular Organic Conductors: Experiment and Simulation

准一维分子有机导体：实验与模拟

• 批准号: 0605339
• 负责人: Michael Naughton
• 金额: $ 48万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0605339&HistoricalAwards=false
• 关键词: Quasi; Molecular; Organic; Conductors; Experiment

NON-TECHNICAL:Everything in our everyday experience with electricity and electronics, from the current running through the toaster oven to the entire information technology revolution, involves electrons that don't "talk" to each other. We have learned to manipulate the electron's charge to the extent we have because we understand how they can be considered non-interacting in spite of the opposites attract, likes repel dictum. Magnetism and superconductivity are spectacular exceptions to this nontalking state, but there are others, and there is much more to learn about the electron. Much of what is new is being found when electron motion is severely confined. We already know that new phenomena arise when strict planar geometry is imposed (two-dimensionality). Realization of this condition in modern semiconducting materials led directly to the discoveries of the integer and fractional quantized Hall effects. The former involves electrons that hardly talk to each other, while for the latter, they are intimately and exquisitely engaged. The present project deals with the nature of the electron when its motion is further confined, to one dimension. There are certain organic and molecular materials that are quite good electrical conductors, and whose structural characteristics are such that the electron motion is very nearly one-dimensional. Again, as a result of geometric constrictions, and the concomitant increase in the importance of quantum mechanical effects on small size scales, new phenomena are arising, especially in strong magnetic fields. This project investigates the behavior of electrons in one-dimensional materials, in particular the nature of the recently-discovered interference-commensurate magnetoresistance oscillation phenomena discovered by the project PI. Knowledge gained from this study will be found to be of much use by technologists wishing to devise nanoscale electronic and electromagnetic structures, for example using carbon nanotubes, where one-dimensional effects will dominate. The project will promote student learning and discovery of the physics of novel materials at several levels, high school, undergraduate, and graduate, through summer internships, fellowships and workshops.TECHNICAL:This individual investigator award supports an experimental project to investigate low-dimensional conductors and superconductors. One goal of this project is to determine the origin of angular magnetoresistance oscillations in quasi-one-dimensional organic metals. Recent experiment and theory suggest a new type of macroscopic quantum effect, interference commensurate oscillations, or perhaps this is a new manifestation of a known effect. Angle-dependent magnetotransport measurements in the highest attainable fields (45 tesla at BC, 60 tesla at NHMFL) will be used to examine in detail the 1D-to-2D dimensional crossover phenomenon seen in TMTSF organic conductors. Also, using nanolithographic and microcantilever techniques, finite size effects, and their impact on spin density waves and spin-triplet superconductivity, will be explored for the first time in these materials. The project will promote student learning and discovery of the physics of novel materials at several levels, high school, undergraduate, and graduate, through summer internships, fellowships and workshops.

非技术性：我们日常使用电力和电子产品的一切，从当前的烤箱运行到整个信息技术革命，都涉及不会互相“交谈”的电子。 我们已经学会了在我们拥有的范围内操纵电子的费用，因为我们了解它们如何被认为是不相互作用的，尽管吸引了对象，但否定了格言。 磁性和超导性是这种非言语状态的壮观例外，但是还有其他，还有更多有关电子的知识。 当电子运动被严重限制时，发现了大部分新事物。 我们已经知道，当强加了严格的平面几何形状（二维）时，就会出现新现象。 现代半导体材料中这种情况的实现直接导致了整数和分数量化大厅效应的发现。 前者涉及的电子几乎不会彼此交谈，而对于后者来说，它们是亲密而精致的。 当电子运动进一步限制为一个维度时，本项目涉及电子的性质。 某些有机和分子材料是相当好的电导体，其结构特性使电子运动几乎是一维的。 同样，由于几何限制以及量子机械效应对小尺寸尺度的重要性的增加，新现象正在引起，尤其是在强磁场上。 该项目调查了电子在一维材料中的行为，尤其是最近被发现的干扰剂量磁化磁性振荡现象的性质。 从这项研究中获得的知识将被发现有很多希望设计纳米级电子和电磁结构的技术人员，例如使用碳纳米管，其中一维效应将占主导地位。 该项目将通过暑期实习，奖学金和研讨会来促进学生学习和发现多个层次，高中，本科生和研究生的新型材料物理学。技术研究员奖支持一个实验性项目，以调查低维导体和超导体。该项目的一个目标是确定准二维有机金属中角磁磁性振荡的起源。 最近的实验和理论提出了一种新型的宏观量子效应，相称的干涉振荡，或者这可能是已知作用的新表现。 最高可达到的场（BC时45个特斯拉，NHMFL的60 Tesla）中的角度依赖性磁转运测量将用于详细检查TMTSF有机导体中看到的1d到2D维度交叉现象。 同样，将首次在这些材料中首次探索使用纳米光刻和微型管理器技术，有限的尺寸效应及其对自旋密度波和自旋三个超导性的影响。该项目将通过暑期实习，奖学金和研讨会来促进学生学习和发现多个层次，高中，本科生和研究生的新型材料物理学。