The visibility of IQHE at sharp edges: Experimental proposals based on interactions and edge electrostatics

Abstract

The influence of the incompressible strips on the integer quantized Hall effect (IQHE) is investigated, considering a cleaved-edge overgrown (CEO) sample as an experimentally realizable sharp edge system. We propose a set of experiments to clarify the distinction between the large-sample limit when bulk disorder defines the IQHE plateau width and the small-sample limit smaller than the disorder correlation length, when self-consistent edge electrostatics define the IQHE plateau width. The large-sample or bulk QH regime is described by the usual localization picture, whereas the small-sample or edge regime is discussed within the compressible/incompressible strips picture, known as the screening theory of QH edges. Utilizing the unusually sharp edge profiles of the CEO samples, a Hall bar design is proposed to manipulate the edge potential profile from smooth to extremely sharp. By making use of a side-gate perpendicular to the two dimensional electron system, it is shown that the plateau widths can be changed or even eliminated altogether. Hence, the visibility of IQHE is strongly influenced when adjusting the edge potential profile and/or changing the dc current direction under high currents in the non-linear transport regime. As a second investigation, we consider two different types of ohmic contacts, namely highly transmitting (ideal) and highly reflecting (non-ideal) contacts. We show that if the injection contacts are non-ideal, however still ohmic, it is possible to measure directly the non-quantized transport taking place at the bulk of the CEO samples. The results of the experiments we propose will clarify the influence of the edge potential profile and the quality of the contacts, under quantized Hall conditions.

Substantially revised version of manuscript arXiv:0906.3796v1, including new figures etc

References in corpus (31)

• Theory of the Fabry-Perot Quantum Hall Interferometer
• Imaging Magnetic Focusing of Coherent Electron Waves
• Incompressible strips in dissipative Hall bars as origin of quantized Hall plateaus
• Self-consistent local-equilibrium model for density profile and distribution of dissipative currents in a Hall bar under strong magnetic fields
• Thomas-Fermi-Poisson theory of screening for latterally confined and unconfined two-dimensional electron systems in strong magnetic fields
• The structure of a single sharp quantum Hall edge probed by momentum-resolved tunneling
• Localization in the quantum Hall regime
• Self-consistent calculation of the electron distribution near a Quantum-Point Contact in the integer Quantum Hall Effect
• Realistic modelling of quantum point contacts subject to high magnetic fields and with current bias at out of linear response regime
• Cryogenic scanning force microscopy of quantum Hall samples: Adiabatic transport originating in anisotropic depletion at contact interfaces
• Microscopics of disordered two-dimensional electron gases under high magnetic fields: Equilibrium properties and dissipation in the hydrodynamic regime
• Quantum Hall effect in a high-mobility two-dimensional electron gas on the surface of a cylinder
• Asymmetric non-linear response of the IQHE
• Potential landscapes and induced charges near metallic islands in three dimensions
• Self-consistent calculation of electric potentials in Hall devices
• Screening Model of Magnetotransport Hysteresis Observed in Bilayer Quantum Hall Systems
• The Interrelation between Incompressible Strips and Quantized Hall Plateaus
• Quantum Hall Resistance Overshoot in 2-Dimensional Electron Gases - Theory and Experiment
• Interaction mediated asymmetries of the quantized Hall effect
• Self-consistent Coulomb picture of an electron-electron bilayer system
• Magnetosubband and edge state structure in cleaved-edge overgrown quantum wires
• Investigations on unconventional aspects in the quantum Hall regime of narrow gate defined channels
• Current direction induced rectification effect on (integer) quantized Hall plateaus
• Screening model of metallic non-ideal contacts at integer quantized Hall regime
• The effect of sample properties on the electron velocity in quantum Hall bars
• Semiclassical analysis of edge state energies in the integer quantum Hall effect
• A systematic study of non-ideal contacts in integer quantum Hall systems
• Local investigation of the energy gap within the incompressible strip in the quantum Hall regime
• A self-consistent microscopic model of Coulomb interaction in a bilayer system as an origin of Drag Effect Phenomenon
• Local density of states of two-dimensional electron systems under strong in-plane electric and perpendicular magnetic fields
• The current polarization rectification of the integer quantized Hall effect