title: Imaging of Coulomb-driven quantum Hall edge states.
abstract: 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 ν=2 QHE state.
authors: Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford California 94305, USA. kejilai@stanford.edu
authors: Keji
authors: K
authors: Lai
authors: Worasom
authors: W
authors: Kundhikanjana
authors: Michael A
authors: MA
authors: Kelly
authors: Zhi-Xun
authors: ZX
authors: Shen
authors: Javad
authors: J
authors: Shabani
authors: Mansour
authors: M
authors: Shayegan