The investigation and control of spin dynamics in semiconductors using ultrafast optical methods

在过去的几年里，世界各地的研究人员一直在为高性能半导体技术追求一个新的方向，包括激光、光子设备、电子逻辑，甚至使用量子信息的新计算机，这些技术都将基于电子的量子力学性质，即自旋。由于这种自旋特性，电子就像一块微小的磁铁，而基于自旋的半导体设备将通过控制磁铁的方向来工作。由于扭转电子自旋方向所需的能量比利用电子的静电电荷在半导体中物理移动电子要少得多，因此基于自旋的晶体管逻辑比传统的基于电荷的逻辑器件的功耗要低得多。现在正在开发一种新的掺杂磁性杂质的半导体，在这种半导体中，电子自旋可以随意排列，并可以用光来控制。这些材料可以将计算机中的逻辑和存储功能整合在一起，从而大大简化了计算机的建造方式。半导体量子点是一种嵌入另一种类型的半导体的纳米级微小碎片，它为我们提供了一种分离单个电子的便捷方法。未来，捕获在量子点阵列中的电子自旋可能会使我们能够开发基于量子信息的新的高度安全的通信系统。拟议的资金将支持新型半导体材料的研究，包括磁性半导体和量子点，这些材料在基于自旋的半导体逻辑、光子学和量子信息领域显示出巨大的应用前景。这些材料将使用一种产生短脉冲光的特殊激光进行研究。这些光脉冲可以用来控制旋转方向，并以极高的时间分辨率“读出”这个方向。这一世界级的研究计划将通过为尖端纺丝技术的开发提供智力基础和高技能的研究人员和技术人员，促进加拿大高科技行业的发展。

Over the last few years, researchers around the world have been pursuing a new direction for high-performance semiconductor technologies, including lasers, photonic devices, electronic logic, and even new computers using quantum information, that would all operate based on a quantum mechanical property of the electron called "spin". By virtue of this spin property, an electron acts as a tiny magnet, and spin-based semiconductor devices will work by controlling the magnet's direction. Since it takes significantly less energy to flip the electron spin direction than to physically move electrons around in semiconductors using their electrostatic charge, transistor logic based on spin would have much lower power consumption than traditional charge-based logic devices. A new class of semiconductors doped with magnetic impurities are now being developed in which electron spins can be aligned at will and controlled using light. These materials could allow logic and memory functions in our computers to be integrated, leading to a drastic simplification in the way that computers are built. Semiconductor quantum dots, which are tiny nanometer-sized pieces of one type of semiconductor embedded in another, provide us with a convenient way to isolate a single electron. In the future, the spins of electrons trapped in arrays of quantum dots may allow us to develop new highly-secure communication systems based on quantum information. The proposed funding will support research into novel semiconductor materials, including magnetic semiconductors and quantum dots, that show great promise for applications in the areas of spin-based semiconductor logic, photonics and quantum information. These materials will be studied using a special laser that produces short bursts of light. These pulses of light can be used to control the spin direction and to "read-out" this direction with extremely high time resolution. This world-class research program will promote growth of the high technology industry in Canada by providing the intellectual foundation and highly-skilled researchers and technicians for the development of cutting-edge spin-based technologies.