Electronic Transport in Graded Gallium Arsenide/Aluminum Gallium Arsenide Heterostructures

通过远距离掺杂GaAs/AlGaAs半导体异质结构，铝（Al）浓度呈抛物线渐变，产生了厚层高迁移率电子气体。所得结构中的电子迁移率可以相当高，因为供体离子位于壁外。除了使用简单的抛物线外，还可以使用电位来绘制更复杂的电子分布图。这样的工作将在本项目中进行，其中电荷和自旋密度分布将被空间调制。这将在高迁移率电子气体的厚层中完成，通过使用叠加在抛物井上的超晶格，以及通过使用电子束光刻制造的周期性电门和磁门结构。由此产生的结构和材料具有非常有趣的电子磁性能，从基础固态物理的角度来看，这是当前的兴趣，并且未来有兴趣用作先进的半导体器件材料。

Thick layers of high mobility electron gas are produced by remotely-doped GaAs/AlGaAs semiconductor heterostructures in which the aluminum (Al) concentration is graded in a parabolic profile. The electron mobility in the resulting structures can be quite high, because donor ions are located outside the wall. More complex electron profiles can be made using potentials other than simple parabolas. Such work will be carried out in this project, in which both the charge and spin density profiles will be spatially modulated. This will be accomplished in thick layers of high-mobility electron gas by using superlattices superimposed on parabolic wells, and by using periodic electric and magnetic gate structures fabricated with electron-beam lithography. The resulting structures and materials have very interesting electron- magnetic properties, of current interest from the fundamental solid state physics perspective, and of future interest for use as advanced semiconductor device materials.