Research on a single electron transistor with self-assembled quantum dots and its prototype fabrication

我们提出了一种嵌入InAs量子点的异质结构晶体管，它可以操纵点中的电子态（包括自旋态）。当自旋注入法可选择通道电子的自旋时，埋设在通道附近的量子点的异质结构场效应晶体管具有量子比特势。这一想法的实现取决于Rashba效应控制和自旋注入的成功。下面对这些重要课题的可行性进行了调查和总结。用舒布尼科夫-德哈斯振荡分析生长在InAs衬底上的InAs量子阱结构中的大自旋轨道耦合。得到的自旋轨道相互作用系数【近似等于】30x10^<-12>eVm。发现其数量远远大于InP上GaAs或InGaAs的数量，几乎与先前的实验相当，在这些实验中，测量的InAs异质结构可能与界面状态或可能的残余应变或可能的几个亚能级相互作用有关。研究了铁磁薄膜向半导体中的“自旋注入”。在低温23℃的分子束外延条件下，在InAs上生长Fe晶体具有较好的自旋注入特性。测量了铁磁体自旋极化电子通过Fe/InAs结注入InAs的电致发光，并验证了自旋注入极化率为【近似等于】20%。

We have proposed a heterostructure transistor embedded with InAs quantum dots which could manipulate electron states (including spin states) in the dot. The heterostructure FET with quantum dots buried in adjacent to the channel, was shown to have apotential of quantum bit ("qubit") when the spin of channel electrons are selectable by spin injection method. Realization of this idea depends on the success of Rashba effect control and spin injection. The feasibility of these important toipcs has been investiagted and summarized below.Large spin-orbit coupling in InAs quantum well structure which was grown on InAs substrate by analyzing Shubnikov-de Haas oscillation. The obtained spin-orbit interaction coefficient was 【approximately equal】 30x10^<-12>eVm. The number was found to be much greater than that of GaAs or InGaAs on InP and almost comparable to the previous experimets where measured InAs heterostructures were associated with possible effects from interface states or possible residual strain or possible interplay of several sublevelsl.The "spin-injection" from ferromagnetic film into semiconductors has been investigated. The crystal Fe growth on InAs by molecular beam epitaxy at low temperature of 23℃ was found to yield better spin injection characteristics. The electroluminescence of spin polarized electrons injected from ferromagnets into InAs therough Fe/InAs junction was measured, and verified spin injection with polarization of 【approximately equal】20%.