Topological Straintronic Devices

非技术性：半导体技术在过去的半个世纪推动了信息时代技术的爆炸性增长。然而，随着器件尺寸接近原子尺度，进一步的进展变得越来越困难。这一挑战需要利用量子现象的新方法。利用量子特性的新型电子器件具有更好的器件可靠性和更低的功耗的潜力。量子技术带来了自己的挑战。特别是，环境影响可能会破坏量子信息，并且需要大量资源进行纠错。拓扑材料由于其独特的性质，为解决这一问题提供了巨大的潜力。特别是，量子态在拓扑上受到对称性的保护，并且不易受到破坏。在这个项目中，弹性应变而不是电场或磁场将被用来控制设备中的电子状态。与基于互补金属氧化物半导体的传统器件相比，逻辑门和其他电子器件预计将更可靠并且使用更少的功率。互动和参与教育推广计划将与研究项目相结合。这些包括科学博客写作和材料和设备展览。这些外展工作将提高公众的科学素养，并提高当地K-12学生的科学欣赏能力。这反过来又会吸引这些学生在教育的早期阶段接触现代科学和技术。最后，将加强代表性不足的群体在科学研究中的参与。技术：该合作研究项目涉及新型应变电子（或应变电子）纳米线器件，该器件基于两类拓扑材料，拓扑晶体绝缘体（TCI）和Weyl半金属（WSMs），它们分别在其表面上承载无质量的狄拉克费米子和在其本体中具有一定手性的Weyl费米子。这些特殊的表面或体态在拓扑上受到对称性的保护，并且对杂质，缺陷和无序相当稳健。利用这些量子/拓扑状态的电子设备相对于常规的基于磁阻器的电子设备可能具有显著提高的可靠性和/或降低的功耗。该项目的总体目标是研究和操纵狄拉克和外尔费米子在拓扑器件中的奇异量子特性，利用可控弹性应变实现低功耗，高可靠性的电子应用。与以前的大块晶体和薄膜的研究相比，拟议的研究将集中在纳米线/nanoribbon为基础的设备，具有特殊功能的应变研究和应用。该项目的成功将建立在两个PI现有的合作，对拓扑材料的广泛熟悉以及材料合成，器件制造，磁输运研究和电子系统理论建模的互补专业知识的基础上。 应变驱动的拓扑相变和相关的量子输运性质的理论和实验相结合的研究将提供新的范例，在电子系统中的基础，潜在的可利用的物理。这项研究也有望代表建立一个新的研究领域，拓扑应变电子学的关键一步：操纵拓扑准粒子与可控的弹性应变。这一奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

Nontechnical:Semiconductor technologies have fueled the explosive growth of information-age technologies over the last half century. Further advances, however, are becoming increasingly difficult as devices dimensions approach atomic scales. This challenge requires new approaches that harness quantum phenomena. Novel electronic devices that exploit quantum properties have the potential for better device reliability and lower power consumption. Quantum technologies bring their own challenges. In particular, environmental effects can corrupt quantum information and significant resources are required for error correction. Topological materials offer great potential to address this problem because of their unique properties. In particular, quantum states are topologically protected by symmetries and are less subject to corruption. In this project elastic strain rather than electric or magnetic fields will be used to control electronic states in devices. Logic gates and other electronic devices are expected to be more reliable and use less power than conventional devices based on complementary metal oxide semiconductors. Interactive and engaging educational outreach programs will be integrated with the research project. These include Science Blog writing and Materials and Device Exhibits. These outreach efforts will promote scientific literacy to the general public and improve science appreciation by local K-12 students. This in turn will attract such students to modern science and technology in the early stages of their education. Finally, the participation of underrepresented groups in scientific research will be enhanced.Technical:This collaborative research project concerns novel strain-electronic (or straintronic) nanowire devices built upon two classes of topological materials, topological crystalline insulators (TCIs) and Weyl semimetals (WSMs), which host massless Dirac fermions on their surfaces and Weyl fermions with definite chirality in their bulk, respectively. These extraordinary surface or bulk states are topologically protected by symmetries and are rather robust against impurities, defects and disorder. Electronic devices exploiting these quantum/topological states are likely to have significantly improved reliability and/or reduced power consumption relative to conventional semiconductor-based electronics. The overall objective of this project is to study and manipulate the exotic quantum properties of Dirac and Weyl fermions in topological devices utilizing controllable elastic strain towards low-power, highly reliable electronic applications. In contrast to previous studies of bulk crystals and thin films, the proposed research will focus on nanowire/nanoribbon-based devices that harbor exceptional features for straintronic studies and applications. The success of the project will be built on the two PIs' existing collaboration, extensive familiarity with topological materials, and complementary expertise on material synthesis, device fabrication, magneto-transport studies, and theoretical modeling of electronic systems. The combined theoretical and experimental studies of strain-driven topological phase transitions and associated quantum transport properties will offer new paradigms for fundamental, potentially exploitable physics in electronic systems. The proposed research is also anticipated to represent a key step in establishing a new research area, topological straintronics: the manipulation of topological quasi-particles with controllable elastic strain.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.