Electron Quantum Correlation in in Semiconductor Quantum-Dot lattice Structures

半导体量子点晶格结构中的电子量子关联

基本信息

批准号：
14350170
负责人：
HORIKOSHI Yoshiji
金额：
$ 7.62万
依托单位：
Waseda University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

Important quantum correlation effects such as quantum Hall effect and fractional quantum Hall effect have been revealed using the semiconductor two-dimensional electron system. In this system, applications to practical devices such as high speed FETs and lasers have also been achieved. In the lower dimensional systems, however, no prominent progress has been achieved in both fundamental research and device applications. A major reason to this lies on their poor geometrical accuracy. In the two-dimensional structures, the thickness of each layer has atomic size accuracy. However, in one- and zero-dimensional structures, side walls are quite rough. Moreover, structures produced by bottom-up.self-assembly process suffer from inhomogeneity and random distribution. In the present research, therefore, we adopted area-selective epitaxy by combining with e-beam lithograph and migration-enhanced epitaxy(MEE). We have succeeded in fabricating high quality one-dimensional electron wires and quantum dot lattices with AlGaAs/GaAs, InAs/GaAs, and InGaAs/GaAs. Atomically flat side walls of nano-structures are formed by utilizing micro-facet structures. To fabricate accurately the structures with designed ones, lateral growth should be minimized. This has been accomplished by optimizing the MEE deposition sequence. One dimensional wires exhibit ballistic transport characteristics. Two dimensional quantum dot lattices show unique transport characteristics. They have proved useful also for two-dimensional photonic crystals.

利用半导体二维电子系统揭示了量子霍尔效应和分数量子霍尔效应等重要的量子相关效应。在该系统中，还实现了在高速FET和激光器等实际器件中的应用。然而，在低维系统中，无论是基础研究还是器件应用都没有取得显着进展。造成这种情况的主要原因在于它们的几何精度较差。在二维结构中，每层的厚度都具有原子尺寸精度。然而，在一维和零维结构中，侧壁非常粗糙。此外，自下而上的自组装过程产生的结构存在不均匀性和随机分布的问题。因此，在本研究中，我们采用了区域选择性外延，结合电子束光刻和迁移增强外延（MEE）。我们已经成功地用AlGaAs/GaAs、InAs/GaAs和InGaAs/GaAs制造了高质量的一维电子线和量子点晶格。纳米结构的原子平坦侧壁是利用微面结构形成的。为了准确地制造设计好的结构，应尽量减少横向生长。这是通过优化 MEE 沉积顺序来实现的。一维线表现出弹道传输特性。二维量子点晶格表现出独特的传输特性。事实证明它们对于二维光子晶体也很有用。