Probing the Quantum Hall State by Electrically Detected ESR and ENDOR in GaAs and Si-MOSFET Heterostructures

这一个人研究人员奖将支持一个项目，该项目旨在阐明量子霍尔体系中关联的二维电子系统(2DES)的性质。这些研究将包括：2DES的磁化强度的测量，电流诱导的动态核极化的研究，以及自旋在Si-MOSFET 2DES中金属-绝缘体转变中的作用。研究中采用的实验方法有电探测电子自旋共振和电探测电子-核双共振。此外，还将建立量子霍尔态电测电子自旋共振机制的磁振子模型，并与信号响应的实验温度和微波功率关系进行比较。实验将在桑迪亚国家实验室制造的高迁移率GaAs/AlGaAs量子阱和Si-MOSFET异质结器件上进行。国家强磁场实验室和佛罗里达大学的P.I.S实验室的仪器将被用来进行拟议的调查。参与这项研究的学生将获得技能，为他们未来在工业和学术界的职业生涯做好准备。此外，他们还将获得在国家设施与科学家合作的经验。对电子在复合半导体材料中流动过程的基本了解是开发性能更好、特性新颖的新型器件的关键。电子的自旋对高性能纳米结构半导体在低温和强磁场下的导电性起着核心作用。在这些条件下(称为量子霍尔区)，电子的流动受到量子力学的强烈影响，其中电子的可用态被限制在一定的能量范围内。这一个人研究人员奖将支持旨在通过微波能量的共振吸收来探测自旋自由度的研究。电子的自旋可以被这种吸收“翻转”，正如德国诺贝尔奖获得者克劳斯·冯·克里辛最先证明的那样，这可以被检测到是导电性的变化。本项目将试图解释这种电学检测的自旋共振效应的机制，并利用它来探测纳米结构半导体中的量子化能级。这项研究可能会对“量子计算”设备或新型“自旋晶体管”的发展产生影响，这些设备的性能比传统设备更高。这些潜在应用的商业化可能会对技术部门产生重大的长期经济影响。因此，美国研究小组在这一研究领域的代表性对国家利益至关重要。参与这项研究的学生将获得技能，为他们未来在工业和学术界的职业生涯做好准备。此外，他们还将获得在国家设施与科学家合作的经验。

This individual investigator award will support a project to elucidate properties of correlated 2 dimensional electron systems (2DES) in the Quantum Hall regime. These studies will include: the measurement of the magnetization of the 2DES, the study of current induced dynamic nuclear polarization, and the role of spin in metal-insulator transitions in a Si-MOSFET 2DES. The experimental methods to be employed in the proposed investigations are electrically detected electron spin resonance and electrically detected electron-nuclear double resonance. Furthermore, a magnon model for the mechanism of the electrically detected electron spin resonance in the quantum Hall state will be developed and compared with the experimental temperature and microwave power dependence of the signal response. Experiments are to be conducted on high mobility GaAs/AlGaAs quantum wells fabricated at Sandia National Labs and Si-MOSFET heterostructure devices. Instrumentation at the National High Magnetic Field Laboratory and in the P.I.'s laboratory at the University of Florida will be employed to carry out the proposed investigations. Students involved with this research will gain skills that will prepare them for future careers in industry and academia. In addition, they will gain the experience of collaborating with scientists at national facilities.A fundamental understanding of the processes associated with the flow of electrons through composite semiconductor materials is key to the development of new types of devices with improved performance and novel characteristics. The "spin" of the electron plays a central role in the conductivity properties of high performance nanostructured semiconductors at low temperatures and high magnetic fields. Under these conditions (referred to as the quantum Hall regime), the flow of electrons is strongly affected by quantum mechanics where the available states of the electron are restricted to certain energies. This individual investigator award will support research aimed at probing the spin degree of freedom by resonance absorption of microwave energy. The spin of the electron can be "flipped" by this absorption, and as was first shown by the German Nobel Laureate Klaus von Klitzing, this can be detected as a change in the conductivity. This project will attempt to explain the mechanism of this electrically detected spin resonance effect, and to use it to probe the quantized energy levels in the nanostructured semiconductor. The research could impact on the development of "quantum computation" devices or new types of "spin transistors" with improved performance over conventional devices. The commercialization of these potential applications could have major long-term economic impact in the technology sector. Thus, representation in this research area by a US research group is crucial to the National interest. Students involved with this research will gain skills that will prepare them for future careers in industry and academia. In addition, they will gain the experience of collaborating with scientists at national facilities.