Collaborative Research: Design and Demonstration of Persistent Spin Textures in Ferroelectric Oxide Thin Film

现代电子学是基于移动电子通过由半导体（如硅）制成的纳米级晶体管。计算能力的指数增长是通过缩小晶体管的尺寸和增加其密度来实现的。随着晶体管的尺寸接近原子尺度，进一步小型化是不可能的。计算和信息处理的另一种途径是利用自旋，这是基本粒子的内在属性。自旋电子学将电子学与自旋结合起来，使信息处理和存储设备具有上级能源效率和减少的热量产生。磁场的限制性特征仍然是在磁性材料中跨纳米尺度传输自旋而不丢失存储的信息。该项目利用相对论量子力学效应-自旋轨道相互作用-沿着晶体对称性来保护自旋在非磁性材料中传播时的状态。该研究小组将联合收割机实验工作与模拟相结合，实现一类用于自旋电子学的新型薄膜氧化物材料。在整个项目中，多层次的学生教学和培训交织在一起。该项目将通过公共宣传活动、课程开发和招募学生参加跨学科实验研究，扩大代表性不足的学生对STEM的参与。教育影响延伸到高中教师，他们将被招募参加研究和开发材料物理模块为他们的教室。这些努力将通过赋予学生未来STEM职业所需的解决问题的技能来影响下一代劳动力。识别超越摩尔定律设备和技术的愿望推动了对一系列替代计算设备的日益关注，包括使用自旋而不是电子的电荷。自旋轨道场的限制特征-基于电子学的一个困难是从传统的半导体和磁性材料获得长寿命和完全可控的自旋。该项目的目标是设计，发现和展示铁电氧化物，其体现了一种受保护的持久自旋纹理，该纹理允许自旋中编码的信息在传播时对腐败具有鲁棒性。该项目的独特之处在于使用原子拓扑结构在具有自旋轨道相互作用的体材料中实现新颖的自旋纹理，而不是通过传统的量子阱结构微妙地平衡多个难以控制的相互作用。该项目将理论、模拟和综合实验与复杂的薄膜氧化物生长方法相结合，以开发自旋纹理的新理论和模型，识别和合成表现出自旋决定的自旋纹理的新型铁电氧化物，并探索自旋纹理的电场可调谐性。该项目的成果包括复杂材料中自旋织构的新描述和预测理论、新型复杂过渡金属氧化物铁电体的实现以及基于自旋的器件的演示。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响评审标准进行评估，被认为值得支持。

Modern electronics are based on moving electrons through nanoscale transistors made of semiconductors such as silicon. The exponential growth in computing power has been realized by shrinking the size of transistors and increasing their density. As the dimensions of transistors approach atomic scales, further miniaturization is not possible. An alternative route to computing and information processing exploits spin, an intrinsic property of elementary particles. Spintronics combines electronics with spin, allowing for devices for information processing and storage that have superior energy efficiency and reduced heat-generation. The limiting feature for the field remains transporting spins across nanoscale dimensions in magnetic materials without losing the stored information. This project exploits a relativistic quantum mechanical effect – spin-orbit interaction – along with crystalline symmetries to protect the state of the spin as it travels in non-magnetic materials. The research team will combine experimental work with simulations to realize a new class of thin film oxide materials for spintronics. Teaching and training of students at multiple levels is interwoven throughout the project. The project will broaden STEM participation by underrepresented students through public outreach events, curriculum development, and recruiting students to participate in interdisciplinary experimental research. The educational impact extends to high-school teachers, who will be recruited to participate in research and develop materials physics modules for their classrooms. These efforts will impact the next-generation workforce by endowing students with the problem solving skills needed for future careers in STEM.The desire to identify beyond Moore’s Law devices and technologies has driven increasing attention on a range of alternative computing devices, including using the spin rather than the charge of an electron. The limiting feature for the field of spin-orbit-based electronics is the difficulty in attaining both long-lived and fully controllable spins from conventional semiconductor and magnetic materials. The goal of this project is to design, discover, and demonstrate ferroelectric oxides embodying a symmetry-protected persistent spin texture, which permits information encoded in the spins to be robust to corruption as they propagate. Unique to this project is the use of atomic topology to achieve the novel spin textures in bulk materials with spin-orbit interactions, rather than by delicately balancing multiple, hard to control, interactions through conventional quantum-well structures. The project couples theory, simulation, and comprehensive experimentation with sophisticated thin film oxide growth methods to develop new theories and models for spin textures, identify and synthesize novel ferroelectric oxides exhibiting symmetry-determined spin textures, and explore electric-field tunability of the spin textures. Outcomes of the project include new descriptive and predictive theories for spin textures in complex materials, realization of novel complex transition metal oxide ferroelectrics, and demonstration of spin-based devices.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.