Strain Engineering of Band Structure and Electronic Properties in Two Dimensional Materials.

二维材料能带结构和电子特性的应变工程。

基本信息

批准号：
1708158
负责人：
Eva Andrei
金额：
$ 42.98万
依托单位：
Rutgers University New Brunswick
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-06-01 至 2020-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1708158&HistoricalAwards=false
关键词：
Strain Engineering Band Structure Electronic

项目摘要

Nontechnical abstractThe discovery of new material properties has historically been an engine for technological advances, prosperity and societal well-being. This prospect has fueled an age-old search for new materials and for techniques to endow existing ones with desirable properties. Traditionally, materials discovery was the result of painstaking exploration of a myriads of chemically synthesized compounds. A new era of materials research was ushered in with the breakthrough isolation of free standing two-dimensional (2D) crystals, such as graphene, and the discovery of a slew of their exceptional physical properties. One of the unique characteristics of these materials is that, with all the atoms residing at the surface, it is possible to access and manipulate their properties by non-chemical means. In particular the introduction of strain by stretching or bending the 2D membrane, can play a crucial role in shaping the material and electronic properties. This research is aimed at developing strategies to induce, to characterize and to exploit the extraordinary potential of strain as a handle for manipulating and engineering electronic and material properties. By modifying the distance between atoms and the geometry of the crystal structure, strain can transform the material properties and has the potential to radically change its behavior. The development of methods to introduce strain in a controlled matter will make it possible to systematically investigate novel strain-induced material properties and unleash their potential for device applications. The research project has a strong educational component that provides excellent opportunities for students and trainees at all levels to gain hands-on experience with advanced scientific equipment and to develop sophisticated data analysis skills. Technical abstractOne of the remarkable qualities of two-dimensional (2D) crystals is the possibility to use external strain to manipulate in a controlled manner their electronic properties. These materials are highly stretchable, have large Young's modulus, low residual stress and enormously large breaking strength which enables them to sustain very large strains without breaking. This research aims at developing techniques to induce, characterize and exploit the extraordinary potential of strain as a handle for manipulating and engineering electronic properties. Introduction of strain by stretching or bending a 2D membrane, makes it possible to change and control the lattice spacing and crystal structure and can play a crucial role in shaping the band structure and the electron dynamics. The team investigates novel properties expected to arise in the presence of strain, such as opening or closing spectral gaps, strain induced superconductivity and topologically protected transport properties by controlling the strength and geometry of the induced strain. Local probes such as scanning tunneling microscopy and Landau level spectroscopy as well as global transport measurements are used to characterize the strain-induced electronic properties. The materials studied include graphene, transition metal dichalcogenides and group IV monochalcogenides, where the effects of strain on the band structure and electron dynamics are expected to be most pronounced.

非技术摘要从历史上看，新材料特性的发现一直是技术进步，繁荣和社会福祉的引擎。这一前景促进了古老的寻找新材料和技术，以赋予现有的材料具有理想的特性。传统上，材料发现是对无数化学合成化合物进行艰苦探索的结果。通过突破性的二维（2D）晶体（例如石墨烯）的突破性隔离，并发现了其出色的物理特性，从而引入了材料研究的新时代。这些材料的独特特征之一是，由于所有原子都位于表面，因此可以通过非化学方法访问和操纵其性能。特别是通过拉伸或弯曲2D膜引入应变，在塑造材料和电子特性中起着至关重要的作用。这项研究旨在制定诱导，表征和利用应变的非凡潜力作为操纵和工程电子和材料特性的手柄的非凡潜力。通过修改原子与晶体结构的几何形状之间的距离，应变可以改变材料特性，并具有从根本上改变其行为的潜力。在受控物质中引入应变的方法的开发将使系统地研究新型应变诱导的材料特性并释放其用于设备应用的潜力是可能的。该研究项目具有强大的教育组成部分，为各个级别的学生和受训者提供了极好的机会，以获得先进的科学设备的动手经验，并开发复杂的数据分析技能。二维（2D）晶体的显着品质的技术摘要是使用外部应变以受控方式操纵其电子特性。这些材料具有高度拉伸的，具有大杨的模量，低残留应力和极大的破裂强度，使它们能够维持非常大的菌株而不会破裂。这项研究旨在开发技术来诱导，表征和利用应变作为操纵和工程电子特性的手柄的非凡潜力。通过拉伸或弯曲2D膜引入应变，使得可以更改和控制晶格间距和晶体结构，并在塑造频带结构和电子动力学方面起着至关重要的作用。该小组研究了在存在应变时预计会产生的新型特性，例如开放或闭合光谱间隙，应变诱导的超导性和拓扑保护的转运性能，通过控制诱导应变的强度和几何形状。诸如扫描隧道显微镜和Landau水平光谱以及全球运输测量等局部探针用于表征应变诱导的电子特性。所研究的材料包括石墨烯，过渡金属二钙化和IV组单钙化物，其中应变对带结构和电子动力学的影响最为明显。