Design and Growth of Si-based Spintronic Materials

本研究的目的是设计和生长新型的硅基自旋电子材料，即掺锰数字铁磁和三层异质结，以及锰/硅超晶格。这些材料有望表现出高自旋极化、高居里温度和大磁阻。这些方法包括第一性原理计算以设计最佳结构构型并研究缺陷和缺陷的影响；利用磁控溅射/电子束混合蒸发和分子束外延技术进行合成；以及结构和磁性表征。智力优势：这个项目有几个智力优点：设计和实现了一类新的硅基自旋电子材料；深入了解了所提出的材料系统中铁磁性的磁相互作用和起源；通过共掺杂空穴调节硅基量子结构中过渡金属原子之间的磁耦合；以及对拟议异质结构中的磁输运性质的计算和测量。广泛的影响：该项目将对技术进步以及教育和培训产生广泛的影响。所提出的材料为制造自旋电子器件提供了一种新的范例，如传感器、开关、存储器和其他集成芯片，其性能优于目前的金属基器件。与作为高科技产业支柱的成熟硅技术相结合，将极大地加快此类器件的开发和应用。技术进步将产生深远的社会和经济影响。学生将通过理论和实验相结合的方式接触到自旋电子材料的电磁性质的广泛知识。培训将有助于将他们塑造成未来的学术和工业领袖，并保持美国在自旋电子学领域的领导地位。

The objective of this research is to design and grow new Si-based spintronic materials,namely Mn doped digital ferromagnetic and trilayer heterostructures, and Mn/Si superlattices. These materials are expected to exhibit high spin polarization, high Curie temperature, and large magnetoresistance. The approaches include first principles calculations to design optimum structural configurations and investigate effects of defects and imperfections; synthesis using hybrid magnetron sputtering/e-beam evaporation and molecular beam epitaxy techniques; and structural and magnetic characterizations.Intellectual Merits:This project has several intellectual merits: design and realization of a new class of Sibased spintronic materials; an in-depth understanding of the magnetic interactions and origins of ferromagnetism in the proposed material systems; prescriptions for tuning magnetic coupling between the transition metal atoms in Si-based quantum structures by co-doping holes; and calculations and measurements of magneto-transport properties in proposed heterostructures.Broader Impact:This project will have broad impacts on technological advancements, and on educationand training. The proposed materials provide a new paradigm for fabricating spintronic devices such as sensors, switches, memory and other integrated chips with superior performance than the current metal-based devices. Integration with the mature Si-technology, the backbone of high-tech industries, will greatly speed up the development and employment of such devices. The technological advancements will have profound social and economical impacts. Students will be exposed to extensive knowledge of electronic and magnetic properties of spintronic materials through combined theoretical and experimental efforts. The training will help to shape them into future academic and industrial leaders and sustain the U.S. leadership in spintronics.