Magnetism and Spin-Dependent Electronic Properties of Tailored Semiconductor Nanostructures

定制半导体纳米结构的磁性和自旋相关电子特性

• 批准号: 1308613
• 负责人: Peng Xiong
• 金额: $ 56万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1308613&HistoricalAwards=false
• 关键词: Magnetism; Spin; Dependent; Electronic; Properties

****Technical Abstract****This project consists of two research thrusts on the magnetic and spin-dependent electronic properties of tailored semiconductor nanostructures. The first utilizes the persistent photoconductivity (PPC) in AlGaAs for a detailed examination of the electronic spin transport/relaxation as a function of its carrier concentration. PPC permits in situ photodoping of the semiconductor channel, thus enabling measurements of spin accumulation and lifetime over broad carrier concentration ranges in one and the same sample. The research is expected to produce comprehensive and detailed knowledge of the spin lifetime as well as various carrier scattering processes relevant to spin relaxation. The second line of research employs high-sensitivity semiconductor Hall magnetometry techniques to study the static and dynamic magnetic properties of transition metal-doped InAs quantum dots (QDs) grown by MBE. The goal of the proposed research is to measure the magnetization of a small array of, even an individual, QDs via an integrated micro/nano Hall magnetometer. The scheme may facilitate a direct correlation of the measured magnetic properties of the QDs with their structural/chemical characteristics, potentially enabling a definitive understanding of the origin of the ferromagnetism in the nano-structured diluted magnetic semiconductors. This grant supports directly the research and education of a PhD student and indirectly other students already involved with this project.****Non-Technical Abstract****Spintronics is an emerging technology which utilizes the electronic spin to provide new and improved electronic device functionality. For more than two decades spintronics in metallic devices has enjoyed great scientific, technological and commercial successes. However, the utilities have been limited to passive devices such as sensors and memory elements. The research into semiconductor spintronics is motivated by the need to produce true three-terminal spintronic logic devices for potential transformative applications such as nonvolatile reprogrammable logic, spin-based opto-electronics, and quantum computation. The research here addresses two key challenges in semiconductor spintronics: coherent manipulation, transport and detection of electron spins in a semiconducting medium and the understanding of the ferromagnetism in transitional metal-doped semiconductors. The first project utilizes light (photo-excitation) to tune the carrier density of an AlGaAs semiconductor channel, enabling a detailed examination of the electronic spin transport/relaxation over a broad carrier concentration range in one and the same sample. The latter employs a high-sensitivity integrated micro/nano Hall magnetometer to study the static and dynamic magnetic properties of a small array of, even an individual, transition metal-doped InAs quantum dots. This grant supports directly the research and education of a PhD students and indirectly other students already involved in this project. It affords them the opportunity to interact closely with the students and researchers at the Institute of Semiconductors, a premiere materials research institution in China.

*技术摘要*这个项目包括两个关于定制半导体纳米结构的磁性和自旋相关电子性质的研究。第一种方法利用AlGaAs中的持久光导(PPC)详细研究了电子自旋输运/弛豫随载流子浓度的变化。PPC允许半导体沟道的原位光掺杂，从而能够在同一样品中的较大载流子浓度范围内测量自旋累积和寿命。这项研究有望产生关于自旋寿命以及与自旋弛豫相关的各种载流子散射过程的全面和详细的知识。第二部分利用高灵敏度的半导体霍尔磁测量技术研究了分子束外延生长的过渡金属掺杂的InAs量子点的静态和动态磁性。这项拟议研究的目标是通过集成的微/纳米霍尔磁强计测量一小群量子点的磁化强度，甚至是单个量子点的磁化强度。该方案可以促进测量的量子点的磁性与其结构/化学特性的直接关联，潜在地使得能够明确地理解纳米结构稀磁半导体中的铁磁性的起源。这笔资助直接支持一名博士生的研究和教育，并间接支持其他已经参与该项目的学生。*非技术摘要*自旋电子学是一项新兴技术，它利用电子自旋来提供新的和改进的电子设备功能。二十多年来，金属器件中的自旋电子学在科学、技术和商业上都取得了巨大的成功。然而，这些实用程序仅限于传感器和存储元件等无源设备。半导体自旋电子学的研究是为了生产真正的三端自旋电子学器件，用于潜在的变革性应用，如非易失性可编程逻辑、基于自旋的光电子学和量子计算。这项研究解决了半导体自旋电子学中的两个关键挑战：半导体介质中电子自旋的相干操纵、输运和检测，以及对过渡金属掺杂半导体中铁磁性的理解。第一个项目利用光(光激发)来调节AlGaAs半导体沟道的载流子密度，使得能够在一个相同的样品中详细地检查在较大的载流子浓度范围内的电子自旋输运/弛豫。后者使用高灵敏度的集成微纳霍尔磁强计来研究过渡金属掺杂的InAs量子点的静态和动态磁性。这笔补助金直接支持博士生的研究和教育，间接支持已经参与该项目的其他学生的研究和教育。它为他们提供了与半导体研究所的学生和研究人员近距离互动的机会，半导体研究所是中国的一流材料研究机构。