Quantum Hall effect in a high-mobility two-dimensional electron gas on the surface of a cylinder
Quantum Hall effect in a high-mobility two-dimensional electron gas on the surface of a cylinder
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DOI：
10.1103/physrevb.79.125320
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发表时间：
2009-03-01
影响因子：
3.7
通讯作者：
Maude, D. K.
中科院分区：
文献类型：
--
作者：
Friedland, K. -J.;Siddiki, A.;Maude, D. K.
研究了圆柱表面高迁移率二维电子气中的量子霍尔效应。这种特殊的拓扑结构导致了沿电流路径沿着空间变化的填充因子，由此产生的不均匀电流密度分布引起了磁输运中的额外特征，例如电阻不对称性和修改的纵向电阻。我们的实验表明，整数填充因子制度中满足的不对称关系也是有效的，在过渡制度的非整数填充因子，从而提出了更一般的形式，这些不对称关系。基于整数量子霍尔效应的屏蔽理论建立了一个模型，该模型允许自洽地计算局部电子密度，从而计算包括沿沿着不可压缩条带的电流的局部电流密度。该模型，其中还包括所谓的“静态趋肤效应”，以占在可压缩区域的电流密度分布可以解释主要的实验观察。由于存在的不可压缩的可压缩的过渡中的散装，该系统的行为总是与传统的Landauer-Buttiker描述，其中散装保持完全绝缘的整个量子化霍尔平台制度的金属。
The quantum Hall effect is investigated in a high-mobility two-dimensional electron gas on the surface of a cylinder. This special topology leads to a spatially varying filling factor along the current path. The resulting inhomogeneous current-density distribution gives rise to additional features in the magnetotransport, such as resistance asymmetry and modified longitudinal resistances. We experimentally demonstrate that the asymmetry relations satisfied in the integer filling factor regime are valid also in the transition regime to noninteger filling factors, thereby suggesting a more general form of these asymmetry relations. A model is developed based on the screening theory of the integer quantum Hall effect that allows the self-consistent calculation of the local electron density and thereby the local current density including the current along incompressible stripes. The model, which also includes the so-called "static skin effect" to account for the current-density distribution in the compressible regions can explain the main experimental observations. Due to the existence of an incompressible-compressible transition in the bulk, the system behaves always metal-like in contrast to the conventional Landauer-Buttiker description, in which the bulk remains completely insulating throughout the quantized Hall plateau regime.