Imaging Transport Resonances in the QHE

High resolution Images

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A 9x9 um hole bubble image showing the in-phase charging signal. The image is taken at 5.0T (ν = 1.26) with a tip voltage of +1.75V. This is a zoomed portion of the image shown in figure 4(c) of our paper.
A 9x9 um hole bubble image showing the lagging-phase charging signal.

Presentations

Presentations are in PDF format or in Powerpoint 2003 format.

Movies

The following are in uncompressed avi format.

Movies showing the evolution of 5x5 um in-phase and lagging-phase scans with bias voltage at 4.8T. Tip voltage is stepped from -0.25 to 1.55V in steps of 0.2V. At a critical voltage, the hole bubble forms, and then continues to grow as the voltage is increased.
More hole-bubble movies showing the evolution of a 10x10 um in-phase and lagging-phase scan with bias voltage at 5.5T. Tip voltage is stepped from -0.35 to 1.65V in steps of 0.1V.
Electron-bubble movies showing the evolution of a 5x5 in-phase and lagging-phase scan with bias voltage at 8T. Tip voltage is stepped from -3.25 to +1.25V in steps of 0.2V.

Simulations

A movie showing the evolution of the density profile as the tip is scanned, as calculated in our simulations. The bulk filling factor is 0.8 and the tip bias is chosen to produce a local filling factor of 1.3 under the tip. The blue color scale represent local densities of ν 1. .

The simulation includes an approximate model of donor correlations from Efros, Pikus, and Samsonidze, Phys. Rev. B 41 8295 (1990). We have used the non-equilibrium model with a Ceff of 1.5x1010 e/cm2.

5x5um images showing the density profile of the 2DES at integer filling showing a typical network of incompressible strips. The disorder model is the same as used above. The first image shows the actual density profile, while the second is threasholded so that ν 1 regions are pink. Several instances are shown where small islands lie inside incompressible strips that separate larger compressible regions.

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