Fundamentals and applications of quantum electronics: exploring an exotic quantum state in nanostructured materials and exploiting know how for new analytical chemical detectors

我的研究重点是包含纳米结构材料(NSM)作为关键元素的电子产品。这是一个高度跨学科的领域，涉及：a)化学--合成/组装纳米结构，对表面进行化学功能化；b)物理--了解新的NSM材料中的电荷传输及其对更传统材料的影响；c)工程--开发新的电子设备和应用。鉴于其跨学科性质，这一领域相对未被探索，并提供了如下所述的重大新机会。我们一直在这一领域做出开创性的贡献，并建议在这些成就的基础上再接再厉，具体如下： 1.NSM和量子电子关联：我的团队是研究NSM中金属-绝缘体转变(MIT)的先驱。在麻省理工学院附近的上一个资助周期中，我们第一次观察到--在任何NSM中--一个具有强关联、离域电子的奇异量子态。关联被广泛认为是高T_c超导电性(铜酸盐)、巨大磁阻(锰氧化物)、奇异超导电性(富勒石、层状有机盐)和其他的关键。这些现象(材料)是历史上研究最多的现象之一，对它们的理解仍然是材料科学中的探索。 考虑到我们对NSM的控制，我们在NSM中观察到的关联电子是一项突破。在这里，我们建议将NSM集成到晶体管中，研究NSM参数与相关状态之间的关系，并设计和研究新的NSM结构。这些研究将探索关联的起源、提高关联存活的转变温度的方法、阐明重要的激发及其在电子离域中的作用等。这些都是重要但仍未解决的问题。这些信息可以帮助更好地总体理解相关材料，甚至可能指向新的此类材料。考虑到他们对科学和技术的巨大兴趣，这将是非常令人兴奋的。 2.微细加工的纳米间隙传感器：在上一个资金周期中，我们开发了一种适用于商业应用的溶液电导检测器。在这一成功的基础上，我们还设计并微制造了一种基于硅基的NanoGap设备，以灵敏地监测分子在其表面的吸附/解吸。获得专利的新颖设计实现了几个特点，包括成本效益、机械稳定性、无标签传感和通过硅烷化实现的强大表面可调性。在目前的资金周期中，我建议用各种“受体”来功能化传感器的表面，并感知选择性/特定的“靶标”。这些结果直接应用于检测饮用水/环境水中的有害物种，以及生物医学和药物开发应用中的各种分子。

My research focuses on electronics that contain nanostructured materials (NSMs) as critical elements. This is a highly interdisciplinary field, which involves: a) chemistry – synthesizing/assembling nanostructures, chemically functionalizing surfaces; b) physics - understanding charge transport in new NSM materials and implications for more traditional materials; and c) engineering – developing new electronic devices and applications. In view of its interdisciplinary nature, this area is relatively unexplored and offers significant new opportunities as described below. We have been making seminal contributions to this area and propose to build on these achievements as follows: 1. NSMs and quantum electron correlations: My group is pioneering the study of metal-insulator transition (MIT) in NSMs. In the last funding cycle, near MIT, we were the first to observe - in any NSM - an exotic quantum state with strongly correlated, delocalized electrons. Correlations are widely believed to be critical for high Tc superconductivity (cuprates), colossal magnetoresistivity (manganites), exotic superconductivity (fullerites, layered organic salts), and others. These phenomena (materials) are some of the most studied in history, and their understanding remains a quest in materials science. Our observing correlated electrons in NSMs is a breakthrough given our control over NSMs. Here, we propose to incorporate NSMs into transistors, study relationships between NSM parameters and the correlated state, and engineer/study new NSM architectures. These studies will explore the origins of correlations, means to raise transition temperatures to which they survive, elucidate important excitations and their roles in electron delocalizaton, etc. These are important but still open questions. Such information can help better understand correlated materials generally and perhaps even point to new such materials. This would be very exciting given their great scientific and technological interest. 2. Microfabricated, nanogap sensor: In the last funding cycle, we developed a conductivity detector for solutions which proved suitable for commercial application. Building on this success, we also designed and microfabricated a silicon-based, nanogap device to sensitively monitor adsorption/desorption of molecules to/from its surface. The patented, novel design enables several features, including cost effectiveness, mechanical stability, label-free sensing and robust surface tunability via silanization. In the present funding cycle, I propose to functionalize the sensor’s surface with various “receptors” and sense selective/specific “targets”. These results have direct application to sense hazardous species in drinking/environmental water and various molecules for biomedical and drug discovery applications.