CAREER: Ultrafast Magnetism in Complex Materials: Coherent and Cooperative Phenomena

职业：复杂材料中的超快磁性：相干和协作现象

• 批准号: 1055352
• 负责人: Jigang Wang
• 金额: $ 60万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1055352&HistoricalAwards=false
• 关键词: CAREER; Ultrafast; Magnetism; Complex; Materials

*** Non-technical ***One major challenge now being posed for fundamental science and technology is to detect, understand and control spins-an ensemble of nanomagnets-in complex systems within one hundred quadrillionth of a second. On one hand, the complex structures made of inter-connected, individual nano-magnetic building blocks can exhibit valuable characteristics and improved functionalities, which are fundamentally different from the sum of their components. On the other hand, such dynamic magnetic processes are at least 1000 times faster than those of the traditional thermal-magnetic processes used thus far, and thereby carry great promise to exceed the upper limit of the magnetic switching speed (0.1-10 GHz) in modern magneto-optical recording industry and enable extremely high-speed magnetic storage/logic devices. This proposal has identified some major opportunities to address these problems via exploiting ultrashort flashes of mid-infrared and far-infrared (trillion cycles per second) electromagnetic radiation. Success in this "ultrafast spin challenge" will reveal as-yet-undiscovered dynamic processes in advanced magnetic systems, and offer ultimate solution towards the problems indentified. The proposal consists of interconnected, specific plans for education and outreach that span high school teachers and their students, undergraduate and graduate level student training; seeks to attract and keep talented students in careers in sciences, and mentor them along their journey to success; develop new courses with complementary hands-on laboratory modules emphasizing ultrafast laser technology, coupled to undergraduate and graduate curriculum.*** Technical ***This proposal explores ultrafast magnetic phenomena in nanoscale and complex magnetic systems using dynamic magneto-optical spectroscopic methods exploiting femtosecond laser excitations. One of the most challenging questions in condensed matter physics and materials science today is whether one can detect, understand and control macroscopic magnetic orders in their highly non-equilibrium, non-thermal states at femtosecond time scales. Such processes are at least 1000 times faster than those of the traditional thermal-magnetic processes used thus far, and thereby carry great promise to exceed the upper limit of the magnetic switching speed (0.1-10 GHz) in modern magneto-optical recording industry and enable extremely high-speed magnetic storage/logic devices. However, thus far how photoexcited coherence and/or non-thermal carriers can substantially modify the macroscopic ordering at such time scales has been poorly addressed to date and most of the predicted exotic properties of photo-driven magnetic systems have yet to be observed. This proposal will explore photoinduced non-thermal, fs magnetic phase transition and significantly advance our knowledge of quantum spin systems driven far from the equilibrium. The proposal consists of interconnected, specific plans for education and outreach that span high school teachers and their students, undergraduate and graduate level student training; develop new courses with complementary hands-on laboratory modules emphasizing ultrafast laser technology.

***非技术***现在针对基本科学和技术提出的一个主要挑战是检测，理解和控制纳米磁体中的复合体系的合奏 - 一秒钟的四分之一十分之一。一方面，由相互连接的单个纳米磁性构建块制成的复杂结构可以表现出有价值的特征和改善的功能，这些功能与其组件的总和根本不同。另一方面，这种动态磁过程的速度至少比迄今为止使用的传统热磁过程的速度快1000倍，从而超过了磁性开关速度（0.1-10 GHz）的巨大希望现代磁光记录行业，并实现极高的高速磁性存储/逻辑设备。该提案通过利用中红外和远红外（每秒万亿个循环）电磁辐射的超短闪光来确定了解决这些问题的一些主要机会。在这种“超快旋转挑战”中的成功将揭示高级磁系统中尚未发现的动态过程，并为缩进的问题提供最终的解决方案。该提案包括涉及高中教师及其学生，本科和研究生级学生培训的互连，具体的教育和外展计划；寻求吸引和使才华横溢的学生从事科学职业，并在成功之旅中指导他们；使用互补的动手实验室模块开发新课程，强调超快激光技术，耦合与本科和研究生课程。激光激发。 当今冷凝物质物理和材料科学中最具挑战性的问题之一是，是否可以在飞秒时间尺度上检测，理解和控制其高度非平衡的非平衡性非平衡状态。 此类过程的速度比迄今为止所使用的传统热磁过程的速度至少要快1000倍，因此在现代磁光录制行业和启用极高的高速磁性存储/逻辑设备。 然而，迄今为止，光激发连贯性和/或非热载体如何在此时间尺度上实质性地修改宏观秩序，迄今为止的地址很差，并且尚未观察到光驱动磁系统的大多数预测的奇特性能。该建议将探索光诱导的非热，FS磁相变，并显着提高我们对远离平衡驱动的量子自旋系统的了解。该提案包括涉及高中教师及其学生，本科和研究生级学生培训的互连，具体的教育和外展计划；通过强调超快激光技术的互补动手实验室模块开发新课程。