Collaborative Research: Strain Based Devices for Switches and Memory Applications

摘要：非技术：在过去的十年里，在实现具有独特性质的新材料类别方面取得了巨大的进步，例如拓扑绝缘体和相变材料。这项提议寻求利用这些新材料类的特性来制造新一代基于应变的设备。器件的应变控制还处于起步阶段，理论预测较多，实验工作较少。此外，许多应变诱导相变的预测还有待验证。我们在制造应变和门控器件方面的成功将使我们能够调整体带结构并将特性传输到金属和绝缘区域，从而为未来的应变和门控器件奠定基础。拓扑材料中实现从绝缘到金属的可逆相变的条件将为从理论上理解这些体系提供重要的信息。实现、表征和测量应变可调系统将使我们能够理解和探索与应变相关的材料特性，如光学和电子存储设备、固态显示器、光子存储器、基于等离子体的电路、光学调制器和计算。参与该项目的本科生、研究生和博士后将在今天研究的前沿接受材料和仪器方面的培训。该项目的成功将提高女性在物理学领域的研究经验。许多在PIS实验室工作的本科生、研究生和博士后都来自代表性不足的群体。PI的综合推广和教育活动将使有才华的高中生接触尖端研究。技术：拓扑绝缘体、拓扑晶体绝缘体和过渡金属二卤化物的独特性质，以及它们潜在的可通过应变和掺杂进行调节，使它们在未来的应用中非常有吸引力。然而，我们利用这种新一代材料的非凡性能的能力在很大程度上取决于我们操纵它们的电子性能的能力。虽然已经提出了一大堆潜在的设备，但到目前为止还没有实现的很少。这一合作研究项目描述了PI计划探索使用应变来控制狄拉克表面状态和相变材料的不同途径。为了实现这一目标，PI将把他们在这些材料类方面的丰富专业知识与先进的测量技术结合起来。该项目的成功取决于分子束外延薄膜生长、低温扫描隧道显微镜表征以及自旋和电荷传输测量之间的紧密反馈回路。3D拓扑绝缘体、拓扑晶体绝缘体和相变材料的薄膜将用扫描隧道显微镜、X射线散射和原子力显微镜等一系列探针进行表征。用于传输测量的应变装置将使用薄膜和剥离的薄片来制造。其目标是通过降低维度和应变来创造具有特定性能的材料，以适应设备应用。

Abstract:Non-Technical:The last decade has seen tremendous advances in the realization of new materials classes with unique properties such as topological insulators and phase change materials. This proposal seeks to harness the properties of these new materials classes to build a new generation of strain-based devices. Strain control of devices is at the beginning stages with many theoretical predictions and little experimental work. Moreover, much of the predictions of strain induced phase transitions are yet to be tested. Our success in creating strain and gated devices will allow us to tune bulk band structure and transport properties into metallic and insulating regimes thereby creating the basis for future straintronic devices. The conditions under which we are able to realize reversible phase transitions from insulating to metallic in topological materials will provide important information for the theoretical understanding of these systems. Realizing, characterizing, and measuring strain tunable systems will allow us to understand and explore strain dependent materials properties for applications such as optical and electrical storage devices, solid-state displays, photonic memories, plasmonic-based circuits, optical modulators, and computing. Undergraduates, graduate students and post-docs involved in this project will be trained on materials and instruments at the forefront of today's research. The success of the project will enhance research experience for women in physics. Many of the undergraduates, graduate students and post-docs working in the PIs' labs are from under represented groups. The PI's integrated outreach and education activities will expose talented high school students to cutting edge research.Technical:The unique properties of topological insulators, topological crystalline insulators, and transition metal dichalcogenides, as well as their potential tunability by strain and doping make them very attractive for future applications. Our ability to harness the extraordinary properties of this new generation of materials however depends heavily on our ability to manipulate their electronic properties. While a whole host of potential devices have been proposed, very few have been realized so far. This collaborative research project describes the PIs plans to investigate different avenues to use strain to control Dirac surfaces states and phase change materials. To achieve this, the PIs will combine their considerable expertise in these materials classes with advanced measurement techniques. The success of the project hinges on a tight feedback loop between molecular beam epitaxy thin film growth, characterization using low temperature scanning tunneling microscopy, and spin and charge transport measurements. Thin films of 3D topological insulators, topological crystalline insulators and phase change materials will be grown characterized with a range of probes including scanning tunneling microscopy, X-ray scattering and atomic force microscopy. Strain devices for transport measurements will be made using both thin films as well as exfoliated flakes. The goal is to create materials with specific properties tailored for device applications through reduced dimensionality and strain.