NER: Enhanced Magnetoabsorption Oscillations in Semiconductor Nanorings

NER：半导体纳米环中增强的磁吸收振荡

• 批准号: 0303969
• 负责人: David Citrin
• 金额: $ 10万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-15 至 2005-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0303969&HistoricalAwards=false
• 关键词: NER; Enhanced; Magnetoabsorption; Oscillations; Semiconductor

This is a Nanoscale Exploratory Research (NER) award that is funded as a result of a proposal submitted to the Nanoscience and Engineering (NSE) initiative. This theoretical research focuses on new phenomena and the resulting functionalities that may be afforded by intrinsic ring-shaped semiconductor nanostructures, called nanorings, based on recently developed fabrication capabilities. In preliminary work, we have predicted that nanorings should exhibit sensitive magneto-optical characteristics in the presence of a static or high-frequency electric field as a magnetic flux threading an intrinsic nanoring is varied. Spectroscopic signatures associated with magnetic field changes of ~0.1 Tesla are evident in the presence of dc electric fields on the order of 1-10kV/cm (consistent with ~1 V potential applied across the structure). The magnetic-field sensitivity is considerably superior to that typically associated with magnetoexcitons in quantum wells where magnetic fields in excess of one Tesla is often needed to affect an appreciable spectroscopic change. Moreover, unlike the analogous transport phenomena, these magneto-optical phenomena are predicted to occur at temperatures up to several tens of Kelvins.This provides a potentially sensitive optical probe of the Aharonov-Bohm effect of neutral excitons in nanorings, in which the magnetoabsorption varies periodically with the threading flux, the period being given by the electron flux quantum hc/e. The demonstration - both theoretical and experimental - of the Aharonov-Bohm effect in the optical properties of semiconductor nanorings, moreover, spurs the search for related phenomena that have traditionally been in the domain of transport. We have begun work investigating the effects of disorder, with an eye on possible Al'tschuler-Aronov-Spivak oscillations, whose period hc/2e is half the electron flux quantum. In addition, effects analogous to universal conductance fluctuations are likely to be observable in the frequency vicinity of an excitonic resonance. Such optical studies allow for superior frequency and wavevector selectivity compared with transport measurements where there is limited control of these parameters.The studies will determine the feasibility of devices exploiting this effect and provide a theoretical basis for related problems. This research is both of fundamental and applied interest across several fields of physics and engineering. The work will be carried out in collaboration with groups in Germany and Switzerland, in addition to Georgia Tech.%%%This is a Nanoscale Exploratory Research (NER) award that is funded as a result of a proposal submitted to the Nanoscience and Engineering (NSE) initiative. This theoretical research focuses on new phenomena and the resulting functionalities that may be afforded by intrinsic ring-shaped semiconductor nanostructures, called nanorings, based on recently developed fabrication capabilities. In preliminary work, we have predicted that nanorings should exhibit sensitive magneto-optical characteristics in the presence of a static or high-frequency electric field as a magnetic flux threading an intrinsic nanoring is varied. The studies will determine the feasibility of devices exploiting this effect and provide a theoretical basis for related problems. This research is both of fundamental and applied interest across several fields of physics and engineering. The work will be carried out in collaboration with groups in Germany and Switzerland, in addition to Georgia Tech.***

这是一项纳米探索性研究（NER）奖，是由提交给纳米科学与工程（NSE）倡议的提案资助的。本理论研究的重点是基于最近发展的制造能力，内在环形半导体纳米结构（称为纳米环）可能提供的新现象和由此产生的功能。在前期工作中，我们预测纳米环在静电或高频电场的作用下会表现出敏感的磁光特性，因为纳米环固有的磁通是变化的。在1- 10kv /cm量级的直流电场下，与~0.1 Tesla磁场变化相关的光谱特征是明显的（与施加在结构上的~ 1v电位一致）。在量子阱中，通常需要超过1特斯拉的磁场才能影响明显的光谱变化，因此磁场灵敏度大大优于与磁激子相关的磁场灵敏度。此外，与类似的输运现象不同，这些磁光现象预计会在高达几十开尔文的温度下发生。这提供了一种潜在的敏感的纳米纳米中中性激子的Aharonov-Bohm效应的光学探针，其中磁吸收随穿线通量周期性变化，周期由电子通量量子hc/e给出。此外，半导体纳米材料光学特性中的Aharonov-Bohm效应的理论和实验证明，刺激了对传统上属于输运领域的相关现象的研究。我们已经开始研究无序的影响，着眼于可能的Al'tschuler-Aronov-Spivak振荡，其周期hc/2e是电子通量量子的一半。此外，在激子共振的频率附近可能观察到类似于通用电导波动的效应。与对这些参数控制有限的输运测量相比，这种光学研究允许更高的频率和波矢量选择性。这些研究将确定利用这种效应的设备的可行性，并为相关问题提供理论基础。这项研究在物理和工程的多个领域具有基础和应用的兴趣。除了佐治亚理工学院外，这项工作将与德国和瑞士的小组合作进行。这是一项纳米级探索性研究（NER）奖，该奖项是由提交给纳米科学与工程（NSE）倡议的提案资助的。本理论研究的重点是基于最近发展的制造能力，内在环形半导体纳米结构（称为纳米环）可能提供的新现象和由此产生的功能。在前期工作中，我们预测纳米环在静电或高频电场的作用下会表现出敏感的磁光特性，因为纳米环固有的磁通是变化的。这些研究将确定利用这种效应的设备的可行性，并为相关问题提供理论基础。这项研究在物理和工程的多个领域具有基础和应用的兴趣。这项工作将与德国和瑞士的团队以及佐治亚理工学院合作进行