Simulations of Complex Order in Thin-Film Magnetic Systems

我研究的主要目的是为了更深入地了解复杂的磁性材料在纳米器件中的应用，从而促进其功能的改进。从高温超导的增强到通过计算机硬盘驱动传感器设备实现TB级的数据存储，对磁性结构和材料的基本了解在近几十年带来了根本性的新见解和技术创新。新的磁性材料不断被发现，对其基本性质的研究将为其在未来技术中的应用提供一条途径。通过广泛的计算机模拟，我们将揭示与纳米磁阻传感器相关的新表征的晶体结构产生的新磁相。这些代表了连接基础物理和应用物理的研究途径。我们的工作将提供对硬盘驱动器自旋阀磁性传感器技术中交换钉扎的微观(原子自旋水平)理解，这项技术在过去20年里一直令研究人员难以理解。这种理解将有助于改进传感器稳定性和性能的方法。*这些材料中感兴趣的基本晶体几何是三角形，它引起磁阻和与电子材料属性相互作用的奇异磁态。利用这种基本的三角单元已经合成了大量的新型磁性晶体结构，它们的性质还有待于充分的研究。*我的团队的努力还将揭示导致这些新材料中异常磁电行为的潜在机制，这些新材料对外加磁场和电场都有反应，并正在进行技术应用评估。这一理解对于未来数据存储容量的增长至关重要。对我的研究活动产生重大影响的是与硬盘制造商西部数据公司以及纪念馆和马尼托巴省的实验小组的持续合作。与加拿大和国外的其他研究人员的互动正在由我与人共同创立并现在领导的组织--磁北组织--推动，该组织定期举办国际研讨会。我所在小组的研究活动将使相关的本科生和研究生能够发展与工业相关的关键编程和高性能计算技能，这将有助于推动加拿大技术的扩展。******

The main purpose of my research is to gain a deeper understanding of complex magnetic materials for nano-device applications which can facilitate improvements in their functionality. From the enhancement of high-temperature superconductivity to enabling terabytes of data storage through computer hard-drive sensors devices, fundamental understanding of magnetic structures and materials has led to radical new insights and technological innovations in recent decades. New magnetic materials continue to be discovered and investigations of their basic properties will provide a path for their applications in future technologies. Through extensive computer modeling, we will reveal novel magnetic phases arising from newly characterized crystal structures that are relevant to nano-scale magnetoresitive-based sensors. These represent avenues of research which bridge fundamental and applied physics. Our work will provide a microscopic (atomic-spin level) understanding of exchange pinning in hard-drive spin-valve magnetic sensor technology which has eluded researchers for the past twenty years. This understanding will facilitate methods to improve sensor stability and performance.**** The fundamental crystal geometry of interest in these materials is the triangle which gives rise to magnetic frustration and exotic magnetic states that interact with electronic material properties. A very large number of novel magnetic crystal structures have been synthesized with this underlying triangular unit and their properties have yet to be fully explored. ****The efforts of my group will also reveal the underlying mechanisms responsible for unusual magnetoelectric behavior in these new materials which respond to both applied magnetic and electric fields and are being evaluated for technological applications. This understanding is critical for the future growth of data storage capacity. A major influence on my research activity is on-going collaborations with hard-drive manufacturer Western Digital Corporation as well as with experimental groups at Memorial and Manitoba. Interactions with other researchers in Canada and abroad are being facilitated by the organization which I co-founded and now lead, Magnetic North, which sponsors regular international workshops. The research activity in my group will enable associated undergraduate and graduate students to develop critical programming and high performance computing skills relevant to industry that will help drive the expansion of technology in Canada. ******