Imaging backscattering through impurity-induced antidots in quantum Hall constrictions

Abstract

We exploit the biased tip of a scanning gate microscope (SGM) to induce a controlled backscattering between counter-propagating edge channels in a wide constriction in the quantum Hall regime. We compare our detailed conductance maps with a numerical percolation model and demonstrate that conductance fluctuations observed in these devices as a function of the gate voltage originate from backscattering events mediated by localized states pinned by potential fluctuations. Our imaging technique allows us to identify the necessary conditions for the activation of these backscattering processes and also to reconstruct the constriction confinement potential profile and the underlying disorder.

References in corpus (7)

• Imaging and controlling electron transport inside a quantum ring
• Imaging Coulomb Islands in a Quantum Hall Interferometer
• Imaging Transport Resonances in the Quantum Hall Effect
• Imaging Electron Interferometer
• Measurement of the Tip-Induced Potential in Scanning Gate Experiments
• Electron interactions in an antidot in the integer quantum Hall regime
• Electron tunneling spectroscopy of a quantum antidot in the quantum Hall regime