CAREER: Tuning Electronic Phases in Layered Complex Oxides

本项目由电子与光子材料和陶瓷项目共同资助。技术：本CAREER项目的主要范围是合成和表征具有强电子相关性的纳米结构复杂钙钛矿氧化物薄膜。在这些系统中控制电子相变需要优异的材料质量，大大降低缺陷密度，超薄层的纳米级载流子限制和原子锋利的界面。研究的重点是人工层状结构，以获得低维电子液体在极端载流子浓度的限制。利用杂化分子束外延生长量子阱异质结构，利用非极性界面处的能带不连续实现约束。目的是探索薄膜生长中可用的材料设计参数，即应变、尺寸限制、化学掺杂和分层方案，如何影响这些二维电子液体的电子相稳定性。先进的光谱和结构表征技术与温度相关的热电和热磁以及磁输运性质相结合，将费米表面修饰与这些人工电子材料系统的原子尺度设计联系起来。非技术：该项目解决氧化物电子新兴领域的基本问题和基础研究挑战。理解由强电子相关引起的现象为发现、定制和利用具有超越传统半导体材料功能的电子材料提供了一条途径。研究结果有望对未来计算方案的节能和超快逻辑器件的发展产生重大影响。项目活动包含一个强大的教育和推广组件嵌入在宾夕法尼亚州立大学现有的推广计划。创建了两个交互式演示包，以说明与研究相关的科学和技术概念。建立了分子束外延系统的功能模型模拟，允许年轻学生使用代表原子的球形物体生长层状结构。开发了一个直观、有形的节拍器交互包，以帮助利用节拍器的同步行为来探索相关效应的各个方面，从而概念化基于相互作用的耦合。演示包的灵活设计可用于各种推广活动，包括博物馆展览、教室和研讨会活动以及科学节。

This CAREER project is jointly funded by Electronic and Photonic Materials and Ceramic programs. Technical: The main scope of this CAREER project aims to synthesize and characterize nanostructured complex perovskite oxide thin films exhibiting strong electron correlation. Controlling electronic phase transitions in these systems requires excellent materials quality with greatly reduced defect densities, nanoscale carrier confinement of ultrathin layers and atomically sharp interfaces. Research is focused on artificial layered structures to achieve low dimensional electron liquids in the limit of extreme carrier concentrations. Hybrid molecular beam epitaxy is employed to grow quantum well heterostructures, where the confinement is achieved using band discontinuities at nonpolar interfaces. The goal is to explore how materials design parameters available in thin film growth, namely strain, dimensional confinement, chemical doping and layering scheme, affect the stability of the electronic phases of these two-dimensional electron liquids. Advanced spectroscopic and structural characterization techniques are employed in combination with temperature-dependent thermoelectric and thermomagnetic as well as magneto-transport properties to correlate Fermi surface modifications with atomic scale design of these artificial electronic material systems. Non-technical: The project addresses fundamental questions and basic research challenges in the emerging field of oxide electronics. Understanding phenomena arising from strong electron correlation provides a path to discover, tailor and utilize electronic materials with functionalities beyond conventional semiconductor materials. Research results are expected to significantly impact the development of energy-efficient and ultrafast logic devices for future computation schemes. The project activities contain a strong educational and outreach component embedded in the existing outreach programs at Penn State. Two interactive demonstration packages are created to illustrate scientific and technological concepts relevant to the research. A functional model analog of a molecular beam epitaxy system is built allowing young students to grow layered structures using spherical objects representing atoms. An intuitive and tangible interactive package of metronomes is developed to help exploring various aspects of correlation effects using the synchronization behavior of metronomes to conceptualize coupling based on mutual interactions. The flexible design of the demonstration packages allow versatile utilization for a variety of outreach activities, including museum exhibits, class room and workshop activities, and science festivals.