CAREER: Breaking and engineering reciprocity in magnetless THz and IR devices using 2D materials

电磁波的传播使现代技术和通信系统成为可能。在许多实际应用中，需要这些波通过非互易通道/设备传播，当源和观测点互换时，这些通道/设备能够表现出不同的响应。隔离器可以保护信号源和天线免受高功率反射的影响，环行器可以将信号分配到不同的输出端，法拉第旋转器可以控制光的偏振。这些组件是电信、国防、医疗保健和航天工业的基本组成部分。不幸的是，打破互易性通常需要与集成电路不兼容的笨重且昂贵的磁性材料。该项目提出了新的方法，通过利用二维材料的激发特性，在不需要外部磁场的情况下，在微米/纳米尺度上打破和设计互易性。研究结果将被应用于开发低成本，紧凑，高效的非互易平台，实现新的功能，并与集成电路和其他光电元件兼容。其主要目标是为非互易器件建立一个新的范式，减少对磁性材料的依赖，并利用不寻常的反应来重塑未来技术的许多领域。教育和推广工作将集中在吸引西班牙裔学生，从K-12到大学，在科学，技术，工程和数学。夏季奖学金将促进本科西班牙裔学生参与一个关于非互易天线的研究项目，让研究生，本科生和高中生互动和分享知识和经验，通过在不同的频率实施类似的概念。关于互惠的研讨会的组织将汇集该领域的顶级专家与研究生和西班牙裔本科生和高中生，使技术讨论和扩大这一令人兴奋的话题对整个社会的影响。 该项目结合并利用二维材料的独特性质，在没有磁偏置的情况下打破和操纵时间反演对称性。首先，非互易响应远远超出目前使用磁光效应可达到的效果，将通过用圆偏振光泵浦受到均匀应变的二维材料来实现。这个平台将允许调查的有效磁偏置下的许多系统的响应比那些在普通实验室获得的大得多，并将使应变工程的实际发展。这种响应将被应用于实现法拉第旋转器和非互易双曲线/相位轮廓超颖表面，从而实现诸如单向巨大光学力和非互易光束转向/透镜化的功能。其次，二维材料的超快场效应将被利用来明智地在空间和时间上调制它们的电特性。时空调制将被应用于实现低损耗，高效，集成的非互易光子和等离子体平台，能够提高电信行业的频谱效率和数据速率。该项目中提出的技术成本低，与集成电路兼容，旨在显著推进非互惠领域的当前前沿。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The propagation of electromagnetic waves has enabled modern technology and communication systems. In many practical applications, it is required that these waves propagate through nonreciprocal channels/devices able to exhibit different responses when source and observation points are interchanged. This is the case of isolators that protect sources and antennas from high-power reflections, circulators able to distribute signals to different outputs, or Faraday rotators that control the polarization of light. These components are fundamental building blocks for telecommunications, defense, health care, and space industries. Unfortunately, breaking reciprocity usually requires bulky and costly magnetic materials that are not compatible with integrated circuits. This project proposes novel approaches to break and engineer reciprocity at the micro/nano-scale by exploiting exciting properties of two-dimensional materials without requiring external magnetic fields. The findings will be applied to develop low-cost, compact, and highly-efficient nonreciprocal platforms that enable novel functionalities and are compatible with integrated circuits and other optoelectronic components. The main goal is to establish a new paradigm for nonreciprocal devices, lessening the dependence on magnetic materials and exploiting unusual responses to reshape many areas of the coming technology. The educational and outreach efforts will focus on engaging Hispanic students, ranging from K-12 to college, in science, technology, engineering and math. Summer fellowships will foster the participation of undergraduate Hispanic students in a research project about nonreciprocal antennas, allowing graduate, undergraduate, and high school students to interact and share knowledge and experiences learnt by implementing similar concepts at different frequencies. The organization of a workshop about reciprocity will bring together top experts in the field with graduate and Hispanic undergraduate and high-school students, enabling technical discussions and broadening the impact of this exciting topic on all society. This project combines and exploits unique properties of two-dimensional materials to break and manipulate time-reversal symmetry in the absence of magnetic bias. First, nonreciprocal responses far beyond what is currently attainable using magneto-optics effects will be realized by pumping two-dimensional materials subjected to uniform strain with circularly-polarized light. This platform will permit to investigate the response of many systems under effective magnetic bias much larger than those attained in common laboratories and will enable the practical development of strain engineering. Such responses will be applied to realize Faraday rotators and nonreciprocal hyperbolic/phase profile metasurfaces, enabling functionalities such as one way giant optical forces and nonreciprocal beam steering/lensing. Second, the ultrafast field effect of two-dimensional materials will be exploited to judiciously modulate in space and time their electric properties. Spatiotemporal modulations will be applied to realize low-loss, efficient, and integrated nonreciprocal photonic and plasmonic platforms able to enhance the spectrum efficiency and data-rate in the telecommunication industry. The technology proposed in this project is low-cost, compatible with integrated circuits, and aims to significantly advance the current frontiers in the field of nonreciprocity.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.