Collective Behavior in Ordered Arrays of Nanostructures - Physics and Technology Opportunities

本项目将从理论和实验两方面研究高有序纳米结构的耦合二维横向超晶格的集体行为。由于在纳米结构材料的选择上有很大的灵活性，这些系统的集体行为可以是电子的或磁性的。这些独特的纳米晶格对新的光电、纳米电子和计算设备具有潜在的技术意义。在过去的一年中，一种新的非光刻模板制造方法被开发出来，用于制造高度有序的阵列或纳米结构的二维横向超晶格-金属和半导体线，以及碳纳米管。在这种能力的基础上，需要新的实验和理论研究来评估这种新的制造能力提供的科学和技术机会；此外，制造技术本身也需要改进。这个项目的主要重点是了解这些纳米晶格内发生的集体行为和相互作用。该项目将通过探索单个纳米结构的器件功能来推进NSF电子、光子学和器件技术项目的目标；从大型纳米元素集合的集体行为中提取系统功能扩展我们制造技术的能力；并为新一代电子产品推进这项技术的前沿。在制造领域，纳米结构晶格的非光刻模板制造方法将得到改进，扩大纳米结构尺寸和间距的范围，从而扩大相邻纳米元件之间的耦合。工程甚至光刻步骤将被引入到这个完全自然的、自组织的纳米制造过程中，以便更好地观察和/或使用系统中的集体行为。这些纳米结构晶格性质的实验探索将使用多种方法进行，包括扫描探针显微镜和光谱学（地形，电子，磁性和光学），以及广域电子，磁性和光学测量。在这些实验中，纳米结构的物理性质将被表征，以帮助理解其集体电子和磁性行为的表现方式。更高级的实验将试图直接观察集体行为。在理论方面，将研究库仑耦合纳米结构阵列的电子行为，以及通过偶极相互作用耦合的磁性纳米结构的畴有序行为。在每种情况下，重点和最终目标将是研究由短程相互作用引起的集体行为，以及这种行为对这些结构的设备应用的影响。一个令人兴奋的长期可能性是将晶格的集体行为用于有用的应用程序-存储设备，信号处理，甚至可能作为新计算概念的测试平台。将要进行的理论工作将为这些新的潜在应用奠定基础，并将指导、告知和使人们能够理解实验结果。总之，这是一个雄心勃勃的项目，旨在为长期工作奠定基础。虽然最终目标极其深远，但调查过程的目的是立即开始并在整个项目期间持续产生科学上有价值和技术上有用的结果。

This project will study the collective behavior of coupled two-dimensional lateral superlattices of highly ordered nanostructures, in both theory and experiment. Due to significant flexibility in the choice of nanostructure materials, these systems' collective behavior could be of either electronic or magnetic nature. These unique nanolattices have potential technological implications for new optoelectronic, nanoelectronic and computational devices. Over the past year, a new non-lithographic template fabrication method has been developed to produce highly ordered arrays or two-dimensional lateral superlattices of nanostructures-metal and semiconductor wires, and carbon nanotubes. Building on this capability, new experimental and theoretical investigations are needed to assess the scientific and technological opportunities which this new fabrication capability provides; additionally, the fabrication technology itself needs refinement. The main focus in this project is to understand the collective behaviors and interactions which take place within these nanolattices. This project will advance the goals of NSF Electronics, Photonics, and Device Technologies program by exploring device functions of individual nanostructures; extracting system functions from the collective behaviors of a large ensemble of nanoelements; extending the capabilities of our fabrication techniques; and advancing the frontier of this enabling technology for a new generation of electronics. In the fabrication area, the methods of non-lithographic template fabrication of nanostructure lattices will be improved, extending the range of nanostructure sizes and spacings, and hence the couplings between adjacent nanoelements. Engineering and even lithographic steps will be introduced into this otherwise completely natural, self-organized nanofabrication process to enable better observation and/or use of the collective behaviors in the system. Experimental exploration of the properties of these nanostructure lattices will be performed using a variety of approaches, including scanning probe microscopy and spectroscopy (topographical, electronic, magnetic and optical), and broad-area electronic, magnetic and optical measurements. In these experiments, the physical properties of the nanostructures will be characterized in order to help understand the ways in which their collective electronic and magnetic behaviors are manifested. More advanced experiments will attempt to observe the collective behavior directly.On the theoretical front, the electronic behavior of Coulomb-coupled nanostructure arrays, andthe domain ordering behavior of magnetic nanostructures coupled via dipole interactions will bestudied. In each case, the focus and ultimate objective will be to study the collective behaviorarising from the short-ranged interactions, and the implications which this behavior has on thedevice applications of these structures. An exciting long-term possibility is the prospect of usingthe collective behavior of the lattices for useful applications-memory devices, signalprocessing, and possibly even as a testbed for new computation concepts. The theoretical work tobe performed will lay a foundation for these new potential applications, and will guide, informand enable understanding of experimental results. In conclusion, this is an ambitious projectdesigned to lay the foundations for long-term work. While the ultimate goals are extremely far-reaching,the process of investigation has been designed to generate scientifically valuable andtechnologically useful results beginning immediately, and continuing through the duration of theproject.