Scanning gate spectroscopy of transport across a quantum Hall nano-island

作者:Martins F*; Faniel S; Rosenow B; Pala M G; Sellier H; Huant S; Desplanque L; Wallart X; Bayot V; Hackens B
来源:New Journal of Physics, 2013, 15: 013049.
DOI:10.1088/1367-2630/15/1/013049

摘要

We explore transport across an ultra-small quantum Hall island (QHI) formed by closed quantum Hall edge states and connected to propagating edge channels through tunnel barriers. Scanning gate microscopy and scanning gate spectroscopy are used to first localize and then study a single QHI near a quantum point contact. The presence of Coulomb diamonds in the spectroscopy confirms that Coulomb blockade governs transport across the QHI. Varying the microscope tip bias as well as current bias across the device, we uncover the QHI discrete energy spectrum arising from electronic confinement and we extract estimates of the gradient of the confining potential and of the edge state velocity.

  • 出版日期2013-1-18