OPNMR- A Local Probe of Spin Physics

OPNMR——自旋物理的局部探针

• 批准号: 0207539
• 负责人: Sean Barrett
• 金额: --
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0207539&HistoricalAwards=false
• 关键词: OPNMR; Local; Probe; Spin; Physics

At low temperatures and at high magnetic fields, electrons in quantum semiconductor heterostructures exhibit a wide variety of interesting phases (e.g., quantum Hall states), due to the combined effects of strong interactions, reduced dimensionality, disorder, and quantum fluctuations. Measurements of the electron spin magnetization and spin dynamics provide important insights into these novel states. This project will directly measure these quantities, on atomic length-scales, using optically pumped nuclear magnetic resonance (OPNMR) spectroscopy. The OPNMR measurements will move in new directions to address emerging questions, e.g., (1) what happens as skyrmions localize?, and (2) what are the electron "stripe" and "bubble" phases? The undergraduate and graduate students who carry out this research activity will receive training while working with advanced instruments, such as a unique NMR magnet (supported by NSF's MRI program). The proposed research is integrated into the PI's educational activities, through teaching and outreach.Today's computers use electronic circuits that process information using the electron's charge. As circuit dimensions are rapidly approaching their smallest possible size, the development of alternative technologies becomes even more important. One approach hopes to make use of the intrinsic magnetism of electrons known as "spin", to build new kinds of devices ("spintronics"), or even a powerful new class of computers ("quantum computers"). To reach these long-term goals, it is imperative to develop local probes of electron spins located inside a semiconductor. This research project will greatly extend the capabilities of one such probe, called optically pumped nuclear magnetic resonance (OPNMR) spectroscopy. These extensions will be driven by the pursuit of fundamental research into the properties of novel phases of an interacting electron system, at low temperature and in strong magnetic fields. The undergraduate and graduate students who carry out this research will receive training while working with advanced instruments, such as a unique NMR magnet (supported by NSF's MRI). The research activity is integrated into the PI's educational activities, through teaching and outreach.

在低温和高磁场下，量子半导体异质结构中的电子表现出各种各样的有趣相（例如，量子霍尔态），由于强相互作用、降维、无序和量子涨落的综合效应。电子自旋磁化强度和自旋动力学的测量提供了重要的见解，这些新的状态。该项目将使用光泵核磁共振（OPNMR）光谱法在原子长度尺度上直接测量这些量。OPNMR测量将朝着新的方向发展，以解决新出现的问题，例如，(1)当Skyrmions本地化时会发生什么？（2）什么是电子“条纹”相和“气泡”相？ 进行这项研究活动的本科生和研究生将在使用先进仪器的同时接受培训，例如独特的NMR磁体（由NSF的MRI计划支持）。 通过教学和推广，这项拟议中的研究被纳入PI的教育活动中。今天的计算机使用电子电路，利用电子的电荷处理信息。随着电路尺寸迅速接近其最小可能尺寸，替代技术的开发变得更加重要。 一种方法是希望利用电子的内在磁性（称为“自旋”）来制造新型设备（“自旋电子学”），甚至是一种强大的新型计算机（“量子计算机”）。 为了实现这些长期目标，必须开发位于半导体内部的电子自旋的局部探针。 这项研究项目将大大扩展这种探针的能力，称为光泵核磁共振（OPNMR）光谱。 这些扩展将由基础研究的追求到相互作用的电子系统，在低温和强磁场的新阶段的属性驱动。进行这项研究的本科生和研究生将接受培训，同时使用先进的仪器，如独特的NMR磁铁（由NSF的MRI支持）。 研究活动通过教学和外联活动纳入PI的教育活动。