Photo Controlled Magnetic Properties of van der Waals Layered Materials

非技术：量子磁体在后硅时代的最新发现，为计算、数据库存储和通信领域的新应用提供了可能。为了实现这些应用，调整这些材料的磁性是物理和材料科学研究的最终目标。一个快速发展的研究领域——利用光来控制和操纵量子磁体的磁性——才刚刚开始。该项目的目标是使用外部光作为控制参数来驱动量子磁相，以推进我们的知识和理解，并控制涌现相。在这个项目中，广泛时间尺度（秒到飞秒）的光激发被用来控制和操纵这些新型材料的磁性。外展活动在埃尔帕索地区的布利斯堡和白沙导弹靶场培训军队人员和退伍军人。该项目进一步提供研究和同行指导机会以及专业发展研讨会，以进一步促进UTEP STEM领域的教育，UTEP主要（81%）是西班牙裔服务机构。技术：新发现的（准）二维（2D）范德华（vdW）磁体显示出与降维相关的意想不到的磁性（单层铁磁性，巨二次谐波产生等），这在最近引起了极大的兴奋。以前的研究表明，电场、静电掺杂、外部压力和混合卤化物化学可以控制这些材料的磁性能。与上述方法不同，已知超快光激发可以更快速有效地控制和操纵材料的磁性，从而允许开发光控自旋电子学。之前的研究人员利用光测量了这些层状材料的磁性。然而，利用光来控制和操纵它们的磁性在很大程度上还未被探索。本研究的主要目的是建立一个全面的基础科学知识和理解，以控制和操纵vdW材料在光激发下的磁性行为。特别重要的是，这项结合实验和理论工作的两个主要目标是：(a)研究准二维和二维CrX3光激发后的磁性，(b)深入了解准二维CrX3光激发后的磁交换相互作用和近磁序的二维相关性。这项工作有可能扩展到其他新兴的vdW磁性金属，无论是准2D还是真2D极限。该项目为埃尔帕索地区布利斯堡和白沙导弹靶场的西班牙裔学生、军人和退伍军人提供研究和教育机会。该奖项反映了美国国家科学基金会的法定使命，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。

Nontechnical: The recent discovery of quantum magnets in the post-silicon era offers the possibility of novel applications in computing, database storage, and communications. To realize these applications, tuning the magnetic properties of these materials is an ultimate goal of physics and materials science research. A rapidly evolving research area, controlling and manipulating the magnetic properties of quantum magnets using light, has just begun. The goal of this project is to use external light as a control parameter to drive quantum magnetic phases, to advance our knowledge and understanding, and to control the emergent phases. In this project, photoexcitation across broad time-scales (seconds to femtoseconds) is used to control and manipulate the magnetic properties of these new classes of materials. Outreach activities train army personnel and veterans at Fort Bliss and White Sands Missile Range in the El Paso region. This project further provides research and peer-coaching opportunities as well as professional development seminars to further foster education in STEM fields in UTEP, which is predominantly (81%) a Hispanic serving institute. Technical: Newly discovered (quasi) two-dimensional (2D) van der Waals (vdW) magnets show unexpected magnetic properties (monolayer ferromagnetism, giant second harmonic generation, etc.,) associated with the reduced dimension, which has generated a great deal of excitement in the recent past. Previous works have shown that electric field, electrostatic doping, external pressure, and mixed halide chemistry can control the magnetic properties of these materials. Unlike the above approaches, ultrafast photoexcitation is known to control and manipulate the magnetic properties of materials much more rapidly and effectively which allows developing light controlled spin electronics. Previous researchers have measured the magnetic properties of these layered materials using light. However, controlling and manipulating their magnetic properties using light has largely been unexplored. The main objective of this research is to establish a comprehensive fundamental scientific knowledge and understanding in controlling and manipulating the magnetic behavior of vdW materials upon photoexcitation. Of specific importance, the two main goals of this combined experimental and theoretical effort are to (a) study the magnetic properties in quasi-2D and 2D CrX3 upon photoexcitation, and to (b) gain in-depth understanding on magnetic exchange interactions and 2D correlations near magnetic order in quasi-2D CrX3 alter upon photoexcitation. This effort has the potential to be extended to other emerging vdW magnetic metals, both at the quasi-2D and true 2D limit. This project provides research and educational opportunities for Hispanic students, army personnel and veterans at Fort Bliss and White Sands Missile Range in the El Paso region.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.