Artificial spin superstructures in semimagnetic CdTe/CdMnTe heterostructures

基于CdTe/CDMnTe的二维电子系统2DES具有有趣的输运性质，这是因为2DES中的电子之间存在很强的spd交换作用和锰的局域磁矩。这导致了自旋向上和向下的电子之间的巨大自旋分裂。在这里，我们计划使用世界上最好的可用的Cd(Mn)Te材料来探索一种新的体系中的输运：具有自旋超结构的电子的输运由空间周期磁场感应。空间周期性磁场是通过铁磁性金属(例如，镝或铁)的纳米条带产生的。除了标准方法外，还通过探索量子霍尔铁磁区和分数量子霍尔区的磁阻反常来测试2DES的质量。这本身就很有趣，因为对半磁半导体中的分数量子霍尔效应的研究到目前为止还没有被探索过。

CdTe/CdMnTe based two-dimensional electron systems 2DES have interesting transport properties owing to the strong sp-d exchange interaction between the electrons in the 2DES and the localized magnetic moments of manganese. This gives rise to a giant spin splitting between spin-up and spin-down electrons. Here we plan to use the world-wide best available Cd(Mn)Te material to explore transport in a novel regime: Transport of electrons having a spin-superstructure which gets induced by a spatially periodic magnetic field. The spatially periodic magnetic field is generated by means of nanopatterned stripes of ferromagnetic metal (e.g. Dysprosium or Iron). The quality of the 2DES is tested – besides standard methods – by exploring magnetoresistance anomalies in the quantum Hall ferromagnet regime and the fractional quantum Hall regime. This is interesting in itself as the investigation of the Fractional Quantum Hall Effect in semimagnetic semiconductors is so far unexplored.