AIIIBV Molecular Beam Epitaxial structures and devices for photonics, nanoelectronics, spintronics and quantum computing.

技术革命带来了个人电脑、高速互联网、数码相机和平板显示器——仅举商品领域为例——其根源可以直接追溯到人造材料薄膜工程技术的进步。高性能的电子器件，如用于智能手机或卫星的晶体管，以及支持沿光纤网络进行超高速信息传输的半导体激光器等光子器件，都是基于采用外延工艺沉积的高度完美的半导体材料晶体多层。在这些器件中，量子级联激光器（qcl）可能代表了外延技术的最大成就，也是固体能带理论和能带工程的最大胜利。这些激光器的活跃区域通常由一千多个不同的薄层组成——量子阱和势垒——有些只有几个原子层厚。尽管每个量子势垒的有效厚度可以控制在原子层的一小部分以内，但是阱和势垒之间的界面质量限制了设备的性能。我们最近展示了在非常困难的太赫兹光谱区域工作的qcl的200K工作温度的世界记录。将其工作温度提高到240K将使这些器件进入主流应用，很明显，为了实现这一目标，需要在原子尺度上控制界面结构。事实上，这种控制对许多其他量子器件至关重要，因为当它们的尺寸缩小时，界面区域开始支配它们的行为。了解和控制分子束外延在原子尺度上的界面形成过程是本研究计划的重点。所获得的见解将用于提高太赫兹qcl、量子热电子晶体管和被确定为革命性拓扑量子计算机候选者的量子结构的性能。由此产生的知识产权、专有技术和源源不断的高素质人才将巩固加拿大高科技产业在全球市场上的强势地位。

The roots of the technological revolution which brought about personal computers, fast internet, digital cameras and flat panel displays-to mention just the commodity sector-can be traced directly to the advances in engineering of very thin films of artificial materials. The highest performance electronic devices, such as transistors used in smartphones or satellites, and photonic devices such as semiconductor lasers supporting the ultra-high speed information transfer along the optical fiber networks, are all based on highly perfect crystalline multilayers of semiconductor materials which are deposited using epitaxial processes. Of these devices the Quantum Cascade Lasers (QCLs) represent perhaps the greatest achievement of the epitaxial technology and the greatest triumph of the band theory of solids and band engineering. The active regions of these lasers are typically made of well over a thousand distinct thin layers - quantum wells and barriers - some just a couple of atomic layers thick. Even though the effective thickness of each such quantum barrier can be controlled to within a fraction of an atomic layer, it is the quality of interfaces between the wells and the barriers that limits the device performance. We recently demonstrated the world's record operating temperature of 200K for QCLs working in the very difficult THz spectral region. Increasing their operating temperature to 240K will bring these devices into the mainstream of applications and it is clear that interfacial structure needs to be controlled at atomic scale to achieve this goal. Such control is in fact of paramount importance to many other quantum devices, since as their size shrinks the interfacial regions start to dominate their behaviour. Understanding and controlling the processes of interface formation at atomic scale in Molecular Beam Epitaxy is the key focus of the proposed research program. Insights gained will be used to improve performance of THz QCLs, Quantum Hot Electron Transistors and quantum structures identified as candidates for revolutionary Topological Quantum Computers. The resulting intellectual properties, know-hows and the steady stream of highly qualified personnel will leverage the strong position of the Canadian high-tech industry in the global markets.