Imaging of Coulomb-Driven Quantum Hall Edge States
Imaging of Coulomb-Driven Quantum Hall Edge States
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DOI：
10.1103/physrevlett.107.176809
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发表时间：
2011-10-19
影响因子：
8.6
通讯作者：
Shayegan, Mansour
中科院分区：
文献类型：
--
作者：
Lai, Keji;Kundhikanjana, Worasom;Shayegan, Mansour
在量子霍尔效应（QHE）体系中，二维电子气（2DEG）的边缘被分成金属和绝缘相间的条带，其宽度由QHE态的能隙和静电库仑相互作用决定.然而，这些亚微米特征的局部探测由于掩埋的2DEG结构而具有挑战性。使用一种新开发的微波阻抗显微镜，我们展示了实空间电导率映射的边缘和体状态。的大小，位置和场的依赖性的边缘带周围的样品周长同意定量与自洽的静电图片。作为磁场的函数的微波图像的演变提供了丰富的微观信息周围的nu = 2 QHE状态。
The edges of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime are divided into alternating metallic and insulating strips, with their widths determined by the energy gaps of the QHE states and the electrostatic Coulomb interaction. Local probing of these submicrometer features, however, is challenging due to the buried 2DEG structures. Using a newly developed microwave impedance microscope, we demonstrate the real-space conductivity mapping of the edge and bulk states. The sizes, positions, and field dependence of the edge strips around the sample perimeter agree quantitatively with the self-consistent electrostatic picture. The evolution of microwave images as a function of magnetic fields provides rich microscopic information around the nu = 2 QHE state.