Electrodynamics of Electron Liquids and Electron Glasses

该个人研究者奖将支持一个实验项目，重点研究具有强电子-电子相互作用、无序和降维的新型材料的低能电动力学。要研究的材料包括：a)金属，如NbSi，其中相互作用和无序的相互作用导致金属-绝缘体过渡和非金属状态，其中量子效应和随机性是必不可少的；b)分子纳米线，严格的一维原子链，如Mo6Se6，其中电子-电子相互作用和/或无序导致相互作用时的Luttinger液体，无序时的Anderson-Mott局域态；c)电子-电子相互作用很强的金属，如UPt3，即所谓的重费米子系统。在后一种材料中，磁相关性可能使材料接近磁不稳定性，这可以被视为量子临界点。在所有情况下，主要的兴趣将是所谓的量子极限，其中与电磁场相关的能量大于热能，这是参数空间的一个区域，迄今为止尚未通过实验探索。参与该项目的研究生和博士后将接受良好的培训，为他们未来在学术界、工业界或政府实验室的职业生涯做好准备。材料中的电子就像原子一样，可以呈现电子液体、电子固体和电子玻璃态。与原子排列相比，这种状态更难实现，同时量子效应在这种集体电子状态的大多数性质中起着更突出的作用。由于电子的电荷，这些状态与电磁辐射强烈相互作用，因此光学研究导致了这些状态的基本信息。同时，这种状态的发展导致材料具有独特的，新颖的光学和电磁特性。通常，对这种辐射的响应发生在光谱范围以下的频率，即微波、毫米波和亚毫米波频率。这项个人研究者奖为一个实验项目提供了支持，该项目将通过开发新的仪器，并在上述频率范围内对发生这种电子状态的材料进行新型实验，来探索物质的各种电子状态。参与该项目的研究生和博士后将接受良好的培训，为他们未来在学术界、工业界或政府实验室的职业生涯做好准备。

This individual investigator award will support an experimental project focusing on the low energy electrodynamics of novel materials with strong electron-electron interactions, disorder and reduced dimensionality. The materials to be investigated include: a) metals such as NbSi where the interplay of interactions and disorder leads to a metal-insulator transition and to a nonmetallic state, where quantum effects and randomness is essential; b) molecular nanowires, strictly one-dimensional chains of atoms such as Mo6Se6 where electron-electron interactions and/or disorder lead to a Luttinger Liquid in case of interactions, and an Anderson-Mott localized state in case of disorder; and c) metals such as UPt3 where electron-electron interactions are strong, the so-called heavy fermion systems. In the latter materials, magnetic correlations may place the materials close to a magnetic instability, which could be viewed as a Quantum Critical Point. In all cases the primary interest will be the so called quantum limit where the energy associated with the electromagnetic field is larger that the thermal energy, a region of the parameter space which has not been explored by experiments to date. The graduate students and post docs working on this project will receive excellent training that will prepare them for future careers in academia, industry, or government laboratories.%%%Electrons in materials can, just like atoms, assume an electron liquid, electron solid and electron glass state. In contrast to atomic arrangements, such states are more difficult to achieve and at the same time quantum effects play a more prominent role in most of the properties of such collective electron states. Because of the electronic charge, such states strongly interact with electromagnetic radiation, thus optical studies lead to fundamental information about such states. At the same time, development of such states lead to materials with unique, novel optical and electromagnetic characteristics. Typically the response to such radiation occurs at frequencies below the optical spectral range, at microwave, millimeter and sub-millimeter wave frequencies. This individual investigator award provides support to an experimental program that will explore the various electron states of matter, by developing new instrumentation and also by conducting novel type of experiments in the frequency ranges mentioned above on materials where such electron states occur. The graduate students and post docs working on this project will receive excellent training that will prepare them for future careers in academia, industry, or government laboratories.