Nanospintronics with quantum dots

电子带有电荷和自旋。利用半导体器件中的电子电荷导致了20世纪的信息革命。该计划旨在为全球在纳米尺度上利用电子自旋的努力做出贡献。电子自旋是一种量子物体，在根据量子力学而不是经典力学运行的设备中具有潜在的用途。这些量子设备需要在纳米尺度上局部化、控制和操纵电子自旋。这可以使用纳米级的半导体结构，半导体量子点来实现。我们将寻求两条主要途径。在第一种方法中，将发展横向量子点理论(场效应晶体管非常小，以至于每个晶体管只包含一个电子自旋)。这样的理论将允许探索这些人造分子，每个分子只有一个自旋，作为小型量子处理器，固态计算机的前身。一旦构建了这样的处理器并处理了信息，就需要存储这些信息。这需要开发嵌入在半导体中的纳米级存储元件。我们能想象到的最小的记忆元件是一个单一的磁性离子。在项目的第二部分，我们将重点发展一种包含可控数量的磁性离子的半导体纳米结构理论。在纳米尺度上控制单个自旋的发展，纳米自旋电子学，可能会导致低功率设备，量子信息设备，以及基于单个磁性离子磁矩的存储设备。

An electron has charge and spin. Exploiting the electron's charge in semiconductor devices led to the 20th century information revolution. This program aims at contributing toward global efforts in exploiting electron spin at the nanoscale. Electron spin is a quantum object and has potential use in devices operating according to quantum, instead of classical, mechanics. These quantum devices require localising, controlling and manipulating electron spins at the nanoscale. This can be accomplished using nanoscale semiconductor structures, semiconductor quantum dots. Two main avenues will be pursued. In the first approach the theory of lateral quantum dots (field effect transistors so small that each transistor contains just one electron spin) will be developed. Such theory will allow the exploration of these artificial molecules with a single spin each as small quantum processors, precursors of solid state computers. Once such processors are constructed and information is processed, it will need to be stored. This requires development of nanoscale memory elements embedded in a semiconductor. The smallest memory element we can imagine is a single magnetic ion. In the second part of the project we will focus on developing a theory of semiconductor nanostructures containing a controlled number of magnetic ions. The development of control over individual spins at the nanoscale, nano-spintronics, may potentially lead to low power devices, to quantum information devices, and to memory devices based on magnetic moments of individual magnetic ions.