Topological Electromagnetic Sensors

翻译后摘要：传感器技术的不断发展，需要创新的方法，降低功耗，提高灵敏度，分辨率工作温度。拓扑绝缘体中轴子电磁耦合的发现为传感器技术性能的大幅提高带来了巨大的希望。这类新材料具有体绝缘能隙和无隙的Dirac锥表面态，它们受到时间反演对称性的保护。与传统半导体不同，由于表面上独特的自旋输运，反向散射被禁止，从而导致令人兴奋的非耗散应用。引人注目的电磁耦合和半整数量子霍尔效应在纳米电子学和自旋电子学中开辟了全新的革命性应用。本计画提出利用拓扑绝缘体中的轴子电磁耦合效应，制作超越传统磁力计性能的超灵敏度磁感测器。智慧价值：本计画的智慧价值包括（i）展示拓扑绝缘体中尚未实验探索的有趣电磁耦合效应;（ii）增进对材料性质的了解，包括表面的磁性掺杂，以及涉及磁性氧化物的异质结构的生长，其中表面间隙打开以引起耦合效应;（iii）探索一种新的量子电容方法，用于检测高温下的表面状态;以及（iv）发明了在环境温度下工作的拓扑传感器，具有前所未有的灵敏度和空间分辨率。这些变革性的概念包括将拓扑绝缘体的低耗散拓扑保护表面态用于电子和自旋电子器件，如磁换能器、电可调电感器和量子计算系统。更广泛的影响：拟议的项目将导致一种新的磁强计技术，利用拓扑绝缘体的体特性和表面态。其高灵敏度、高空间分辨率和低功耗的性能可以满足传感器技术的要求。该项目的成功有望在脑电波检测等医学研究和军事监视方面具有潜在的应用价值。该项目的开发可能会提高EPSCoR州#8722（爱荷华州）在磁传感器设备领域的竞争力。除了技术影响外，该计划还有一个强大而全面的教育组成部分。学生将获得宝贵的研究经验，在电气工程，物理学和材料科学这一高度跨学科的领域，导致加强培训和能力，追求创新的整个职业生涯。PI将通过爱荷华州州立大学现有的外联方案“科学界”和“妇女参与科学和工程方案”，从代表性不足的群体中招收学生，特别是女学生，创造一个多元文化的环境。全额学费，研究援助和资源将为他们的教育提供。学生可以有充分的机会学习最先进的传感器技术，并获得拓扑绝缘体的实践经验。这些经验将扩大他们的科学视野，从而成为他们未来职业生涯的宝贵财富。该计划的成果将被纳入传感器技术课程，并通过同行评审的出版物在会议上传播。PI还将积极参与爱荷华州的K-12计划，并继续提供有关纳米技术和磁性的小型讲座。以有趣的示范形式介绍拓扑电磁传感器的研究前沿，激发学生对科学技术的好奇心、创造力和热情。

Abstract:The continuing evolution of sensor technology requires innovative approaches for reducing power consumption and improving sensitivity, resolution & operating temperature. The recent discovery of axion electromagnetic coupling in topological insulators holds great promise for drastic improvement of performance in sensor technology. This new class of materials has a bulk insulating energy gap and gapless Dirac-cone surface states which are protected by time-reversal symmetry. Unlike in traditional semiconductors, back-scattering is prohibited because of unique spin transport on the surfaces, leading to exciting non-dissipative applications. The striking electromagnetic coupling and half-integer quantum Hall effects open up completely new and revolutionary applications in nanoelectronics and spintronics. This project proposes to exploit the axion electromagnetic coupling effect in topological insulators and to build ultra-sensitive magnetic sensors that surpass the performance of traditional magnetometers.Intellectual Merit: The intellectual merit of this project includes (i) the demonstration of the intriguing electromagnetic coupling effect in topological insulators that has not yet been experimentally explored; (ii) the improved understanding of material properties including magnetic doping of surfaces, and the growth of heterostructures involving magnetic oxides in which the surface gap is opened to invoke the coupling effect; (iii) the exploration of a novel quantum capacitance approach for the detection of surface states at high temperatures; and (iv) the invention of topological sensors operating at ambient temperature with unprecedented sensitivity and spatial resolution. The transformative concepts include the use of low-dissipation topologically protected surface-states of topological insulators for electronic and spintronic devices such as magnetic transducers, electrically tunable inductors, and quantum computation systems.Broader Impacts: The proposed project will lead to a new magnetometer technology that exploits bulk properties and surface states of topological insulators. The high sensitivity, high spatial resolution and low-dissipation performance can satisfy the demanding requirements in sensor technology. The successful project is expected to have potential applications in medical research such as brain wave detection and in military surveillance with an enhanced magnetic sensitivity at low fields. The development of this project can potentially improve the competitiveness of the EPSCoR state #8722 (Iowa State) in the area of magnetic sensor devices. Besides the technological impacts, the program has a strong and comprehensive education component. Students will gain invaluable research experience in this highly interdisciplinary area of electrical engineering, physics, and materials science, leading to enhanced training and ability to pursue innovations for the entirety of their careers. The PI will create a multicultural environment by recruiting students from underrepresented groups, particularly female students, through the existing outreach programs "Science Bound" and "Program for Women in Science and Engineering" at Iowa State University. Full tuitions, research assistances and resources will be supplied for their education. The students can have ample opportunities to learn state-of-the-art sensor technology and gain hand-on experience on topological insulators. Such experience will broaden their scientific horizons and thus become invaluable assets to their future careers. The outcomes of the program will be incorporated into a course on sensor technology and disseminated in conferences & through peer-reviewed publications. The PI will also actively participate in the K-12 program at Iowa State and continue to offer mini-lectures on nanotechnology and magnetism. Research frontiers of the topological electromagnetic sensors can be included as interesting demonstrations, aiming to stimulating students' curiosity, creativity, and enthusiasm in science and technology.