Materials World Network: Engineering the Spintronic Properties of Semiconductor Quantum Dots

通过这项材料世界网络奖，来自美国，巴西，加拿大和阿根廷的匹兹堡大学科学家将研究专为自旋电子和量子信息应用量身定制的工程量子点系统，并由材料研究部的电子材料计划和国际科学与工程办公室的美洲计划共同资助。 这个与匹兹堡大学、巴西国立Luz Sincrotron大学、加拿大圭尔夫大学和阿根廷布宜诺斯艾利斯大学的科学家合作的项目将开发两种材料系统：InAs：GaAs和Ge：Si量子点。 每个系统在自旋电子学应用方面都有独特的优势和挑战，以及通过生长可以操纵这些属性的程度。InAs：GaAs量子点将使用一种方法生长，该方法将产生高度单分散的量子点，其密度可以在两个数量级上变化。 Ge：Si量子点将使用一种新的方法生长，其中SiC纳米模板可控地放置在Si（100）表面上，然后在模板表面上“定向”自组装Ge岛。 这些点的表征将以各种互补的方式进行，包括隧道显微镜/光谱学，光致发光/吸收光谱学和电容电压测量（以提取量子点的g张量以及确定电子占有率）。 高分辨率X射线测量将提供有关量子点内部组成的关键结构信息。将开发用于产生、操纵和测量量子点自旋的自旋电子器件原型。 这些简单的设备将被用来测量自旋相干时间，g-张量调制共振在单量子点，和测试机制的单电子自旋读出（使用自旋相关隧道测量在微波频率）。拟议的研究重点是定制半导体量子点的生长，以优化性能的自旋电子和量子信息应用。在过去的二十年里，控制量子点的性质一直是材料科学的首要目标。自旋电子学和基于自旋的量子信息科学和技术受到广泛的国际关注，拟议的合作将正式化并加强美洲内部的联系。研究生可能会从这个国际合作计划中获得最大的好处。在国外旅行期间，学生将分享他们的专业知识，文化，科学方法以及他们的知识和文化视野。在这个交流计划中培养的纽带旨在贯穿整个职业生涯。

With this Materials World Network award to University of Pittsburgh scientists from US, Brazil, Canada and Argentina will study engineered quantum dot systems that have been specifically tailored for spintronic and quantum information applications, and is co-funded by the Electronic Materials program in the Division of Materials Research and the Americas program in the Office of International Science and Engineering. This collaborative project with scientists from University of Pittsburgh, Laboratorio Nacional de Luz Sincrotron (Brazil), University of Guelph (Canada), and University of Buenos Aires (Argentina) will develop two material systems: InAs:GaAs and Ge:Si quantum dots. Each system has unique strengths and challenges in terms of spintronic applications, and the degree with which these properties can be manipulated through growth. InAs:GaAs quantum dots will be grown using an approach that will create highly monodisperse quantum dots with densities that can be varied over two orders of magnitude. Ge:Si quantum dots will be grown using a novel approach in which SiC nanotemplates are placed controllably on the surface of Si(100), followed by "directed" self-assembly of Ge islands on the templated surface. Characterization of these dots will be performed in a variety of complementary ways, including tunneling microscopy/spectroscopy, photoluminescence/absorption spectroscopy, and capacitance-voltage measurements (to extract the g-tensor of quantum dots as well as determine the electron occupancy). High-resolution x-ray measurements will provide crucial structural information about the internal composition of the quantum dots. Prototype spintronic devices will be developed for producing, manipulating and measuring spin in quantum dots. These simple devices will be used to measure spin coherence times, g-tensor modulation resonance in single quantum dots, and test mechanisms for single electron spin readout (using spin-dependent tunneling measured at microwave frequencies).The proposed research focuses on tailoring the growth of semiconductor quantum dots in order to optimize properties for spintronic and quantum information applications. Control over the properties of quantum dots has been a foremost goal in material science over the last two decades. Spintronics and spin-based quantum information science and technology share widespread international attention, and the proposed collaboration will formalize and strengthen the ties within the Americas. Graduate students are likely to receive the greatest benefit from this international collaborative program. During their trips abroad, students will share their expertise, cultures, approaches to science, and their intellectual and cultural horizons. The bonds fostered within this exchange program are designed to endure throughout an entire professional career.