Exploring Spin-Orbit Coupling and Correlated Phenomena in Iridate-Based Ferroelectric Transistors and Tunnel Junctions

非技术摘要：在重过渡金属氧化物中，如Irates，电子自旋与其轨道运动是强烈耦合的。当这种效应与其他涉及电荷和结构顺序的相互作用竞争时，可以显著改变材料的电子和磁性。这项研究项目探索了两种材料策略来理解、控制和增强Irate基复合材料中的这些耦合。所获得的知识可以用来设计超越当前信息技术性能限制的新型纳米器件。这项研究为研究生、本科生和高中学生提供了令人兴奋的研究机会，让学生接触到尖端的纳米科学和材料研究。综合宣传部分旨在促进K-12 STEM教育和向公众传播科学。这些努力包括创建一个以一个十几岁的女孩学习相关器件概念及其在现代电子技术中的应用为中心的网络漫画故事，并在FunSize物理网站上发表一篇关于相关主题的帖子。技术摘要：本研究项目的目标是利用铁电场效应晶体管和铁电隧道结两种原型器件结构来探测和控制5d过渡金属氧化物SrIr03和Sr2IrO4外延薄膜中的自旋轨道耦合和关联驱动现象。研究活动包括考察载流子密度、晶格应变和缺陷在SrIrO_3自旋输运中的单独作用，调制Sr2IrO_4中的磁各向异性，寻找载流子密度驱动的金属绝缘体和磁性相变，以及探索Ir酸盐基隧道结的隧道特性。这项研究包括复杂氧化物异质结构的先进外延沉积、纳米器件制造、扫描探针显微镜、变温磁输运和隧道光谱研究。所提出的努力将促进对自旋-轨道耦合及其与重金属过渡金属氧化物中各种相关能量的竞争的基本理解。所获得的知识可用于开发基于氧化物的新型非易失性或多功能电子和自旋电子应用。

Non-Technical Abstract:In heavy transition metal oxides such as iridates, the electron spin is strongly coupled with its orbital motion. This effect, when competing with other interactions involving the charge and structural order, can significantly alter the material's electronic and magnetic properties. This research project explores two material strategies to understand, control and enhance these couplings in iridate-based composite materials. The gained knowledge can be utilized to design novel nanoscale devices that transcend the performance limits of the current information technology. The research provides exciting research opportunities for students at the graduate, undergraduate and high school levels, exposing the students to cutting-edge nanoscience and materials research. The integrated outreach components aim at promoting the K-12 STEM education and disseminating science to the general public. The efforts include creating a web-based comic story centered around a teenage girl learning the related device concept and its application in modern electronic technology, and contributing a post on the related topic to the Funsize Physics website.Technical Abstract:The goal of this research project is to probe and control the spin-orbit coupling and correlation-driven phenomena in epitaxial thin films of the 5d transition metal oxides SrIrO3 and Sr2IrO4 using two prototype device structures, the ferroelectric field effect transistors and the ferroelectric tunnel junctions. The research activities include examining the individual roles of carrier density, lattice strain, and defects in the spin transport of SrIrO3, modulating the magnetic anisotropy in Sr2IrO4, searching for carrier density-driven metal-insulator and magnetic phase transitions, and exploring the tunneling characteristics of iridate-based tunnel junctions. This research involves advanced epitaxial deposition of complex oxide heterostructures, nanoscale device fabrication, scanning probe microscopy, variable temperature magnetotransport and tunneling spectroscopy studies. The proposed efforts stand to advance the fundamental understanding of spin-orbit coupling and its competition with various correlated energies in the heavy transition metal oxides. The gained knowledge can be leveraged to develop novel oxide-based nonvolatile or multifunctional electronic and spintronic applications.