Molecular Nanoelectronics: Simulation from Molecules to Circuits

该研究的目标是建立一个由分子电子学化学、分子尺度电子传导物理学、先进电子结构、输运性质和实验协议以及硅器件和电路技术专家组成的合作团队，以应对量子尺度电子学的挑战。这将需要涉及多个长度和能量尺度的建模和仿真，从原子哈密顿量开始，到复杂的电路。利用分子自组装，界面控制和扫描探针的使用方面的进步，我们将检查大块接触之间的分子桥，并将实验中观察到的一般特征与模拟相关联，通过分子耦合到大块金属引线的格林函数计算兰道尔电导。最近，有趣的，潜在的有用的，可逆开关特性已经被观察到，将进行理论分析。该系统通常由硬接触（半导体或金属）和可能表现出动态结构修饰的软分子组成。这个多学科、小组合作的目标是：i)理解硬接触之间分子桥的物理和电子结构以及振动相互作用，ii)对现在观察到的有趣的非线性分子i - v特征进行理论理解，并将它们与分子结构联系起来，iii)设计提取基于物理的，从分子电子器件的哈密顿量的电路模型和iv)使用这些知识和开发的模拟工具来识别从器件和电路角度来看有前途的分子结构。对如何将电子器件和电路功能与分子结构联系起来的理解的发展是拟议研究的关键目标。这项工作的其他重要组成部分和产品包括：i)为分子纳米电子学开发一套“社区代码”，强调分子器件的结构/功能关系，并将它们连接到电路和系统的宏观世界；ii)一种方法，允许研究人员提出特定的结构、电极和界面连接，预测器件的电性能，并提取电路模型；iii)一个独特的软件基础设施，计算电子中心，允许用户通过WWW浏览器访问和操作模拟工具，iv)一系列课程将通过多学科的努力得到丰富和扩展，v)与学术界（耶鲁大学里德学院）和工业界的领先实验工作密切互动，vi)与NIST小组合作，提供先进分子电子结构方法的专业知识，vii)与国际中心合作，特别是委内瑞拉中央大学，材料世界模块计划中的高中水平教学模块，以及与半导体研究公司和个别半导体公司的密切互动，为电子工业带来自组装分子电子学的想法和方法。

The objective of the proposed research is to establish a collaborative team of experts from the chemistry of molecular electronics, the physics of electronic conduction at the molecular scale, advanced electronic structure, transport properties and experimental agreement, and silicon device and circuits technology to address the challenges of electronics at the quantum scale. This will require modeling and simulation involving multiple length and energy scales, starting from atomic Hamiltonians and going to complex circuits. Leveraging advances in molecular self-assembly, interfacial control, and the use of scanning probes, we will examine molecular bridges between bulk contacts, and relate the general features observed in experiments to simulations which compute the Landauer conductance from the Green's function of the molecule coupled to bulk, metal leads. Very recent, interesting, and potentially useful, reversible switching characteristics that have been observed will be analyzed theoretically. The systems typically consist of hard contacts (semiconductors or metals) and soft molecules that may exhibit dynamic structure modification. The objectives of this multi-disciplinary, small group effort are: i) to understand the physical and electronic structure and vibronic interactions of molecular bridges between hard contacts, ii) to develop a theoretical understanding of the interesting nonlinear I-V characteristics of molecules that are now being observed and to relate them to the structure of the molecule, iii) to devise methods for extracting physics-based, circuit models from the Hamiltonian of molecular electronic devices and iv) to use this knowledge and the simulation tools developed to identify molecular structures that are promising from a device and circuits perspective.The development of an understanding of how to relate electronic device and circuit function to molecular structure is the key objective of the proposed research. Other important components and products of this work include: i) the development of a set of 'community codes' for molecular nanoelectronics that emphasize the structure/function relationship of molecular devices and that connect them to the macroscopic world of circuits and systems, ii) a methodology to allow a researcher to suggest a particular structure, electrodes, and interfacial linkages, predict the electrical performance of the device, and to extract a circuit model, iii) a unique software infrastructure, The Computational Electronics Hub, that will permit users to access and operate simulation tools through a WWW browser, iv) a set of courses that will be enriched and expanded by this multidisciplinary effort, v) close interactions with leading experimental efforts in academia (Reed at Yale) and industry, vi) a partnership with the NIST group to provide expertise in advanced molecular electronic structure methods, vii) collaboration with international centers, particularly the Central University of Venezuela, viii) A high-school level teaching module in the Materials World Modules program, and ix) close interactions with the Semiconductor Research Corporation and with individual semiconductor companies to bring ideas and approaches of self-assembled molecular electronics to the electronics industry.