Studies of Electronic Excitations in Low-Dimensional Systems by Optically Detected Resource Spectroscopy

小行星9722625 这是一个新的项目，其中光学检测共振（ODR）光谱，它结合了近红外/可见光光子检测与远红外激发的灵敏度，将被用来研究与低维半导体系统中电子和空穴的多体相互作用有关的基本问题。 极低密度带内电子激发 光激发载流子和载流子复合物的性质可以用这种方法研究。 具体项目包括：高磁场中中性和带电激子的内部状态;过量电子和空穴对激子状态和金属-绝缘体转变的影响;通过施主杂质对远红外激发的影响在整数和分数量子霍尔效应区域中的许多体效应;以及ODR机制。 这项研究将产生有关激子、过量载流子对其内部状态的影响、能量转移到基态复合路径的机制以及深入了解低温和高磁场下电子的任意体基态的独特信息。 %这是一个新的项目，其中一个新的技术，结合敏感的 附近 红外/可见 检测 与 光谱远红外区的共振吸收，光学检测 共振（ODR）光谱，将 被 使用 研究小（几十纳米）人造半导体结构中电荷载流子的允许能量状态。 这些结构的独特的电子和光学性质由量子力学和电荷载流子、电子或空穴的相互作用决定。 这项研究将产生独特的信息，并提高对电子和空穴结合在一起的能量状态的理解（所谓的激子），多余的自由电子和空穴对这些状态的影响，以及激发电子时能量是如何被吸收的空穴系统被转移回最低能量状态，随后导致复合和发光。 这项工作也将提供深入了解有趣的多电子态，存在于低温和高磁场，量子霍尔和分数量子霍尔状态。 ***

9722625 McCombe This is a new project in which optically Detected Resonance (ODR) spectroscopy, which combines the sensitivity of near IR/visible photon detection with far IR excitation, will be used to investigate basic issues related to many-body interactions of electrons and holes in low-dimensional semiconductor systems. Intraband electronic excitations of very low densities of photoexcited carriers and carrier complexes can be investigated in this way. Specific projects include: internal states of neutral and charged excitons in high magnetic fields; effects of excess electrons and holes on excitonic states and the metal- insulator transition; many body effects in the integer and fractional quantum hall effect regimes through the influence of donor impurities on the far IR excitations; and ODR echanisms. This research will yield unique information about excitons, effects of excess carriers on their internal states, mechanisms of energy ransfer to the ground state recombination paths, and insight into the any-body ground states of electrons at low temperatures and high magnetic fields. %%% This is a new project in which a novel technique that combines sensitive near infrared/visible detection with resonant absorption in the far infrared region of the spectrum, Optically Detected Resonance (ODR) spectroscopy, will be used to investigate the allowed energy states of charge carriers in small (tens of nanometers) man-made semiconductor structures. The unique electronic and optical properties of these structures are determined by quantum mechanics and the interactions of the charge carriers, electrons or holes. This research will yield unique information about and improved understanding of the energy states of electrons and holes bound together (the so-called exciton), the effects of excess free electrons and holes on these states, and how e nergy absorbed in exciting the electron-hole system is transferred back to the lowest energy states and subsequently leads to recombination and light emission. This work will also provide insight into the interesting many-electron states that exist at low temperature and in high magnetic field, the Quantum Hall and Fractional Quantum Hall states. ***