New approach to the physics of two dimensional electron systems

我们研究了高迁移率硅二维电子系统中的磁输运，通过原位倾斜的样品相对于磁场。在非整数充填因子的朗道水平交叉过程中，纵向电阻率有明显的下降。这表明在相关朗道能级上的电子在重合时变得局域化。研究了高迁移率Si/SiGe材料在低温下二维电子的回旋共振，其直流电阻率具有金属温度依赖性。弛豫时间与输运散射时间相似，与温度呈负相关。利用磁输运测量方法研究了劈裂GaAs表面单原子层Pb薄膜的二维超导性。结果被解释为预测二维金属具有大Rashba自旋分裂的非均匀超导状态。

We study magnetotransport in a high-mobility Si two-dimensional electron system by in situ tilting of the sample relative to the magnetic field. A pronounced dip in the longitudinal resistivity is observed during the Landau-level crossing process for noninteger filling factors. This indicates that electrons in the relevant Landau levels become localized at the coincidence.Cyclotron resonance of two-dimensional electrons is studied at low temperatures for a high-mobility Si/SiGe which exhibits a metallic temperature dependence of dc resistivity. The relaxation time shows a negative temperature dependence, which is similar to that of the transport scattering time.Two-dimensional (2D) superconductivity was studied by magnetotransport measurements on single-atomic-layer Pb films on a cleaved GaAs surface. The results are explained in terms of an inhomogeneous superconducting state predicted for 2D metals with a large Rashba spin splitting.