We study conductance fluctuations of the edge-state sheath that forms in the integer quantum Hall effect from the coupled edge states of a GaAs/AlxGa1-xAs multilayer. Comparison of the measured variance in the vertical conductance to recent theoretical predictions for mesoscopic fluctuations suggests dephasing lengths of 1-10 μm around the sheath perimeter at low temperatures. However, inconsistencies in the estimated inelastic lengths indicate that present understanding of dephasing on the sheath is incomplete.
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Acknowledgements—We acknowledge helpful conversations with L. Balents, M. P. A. Fisher, S. J. Allen, and S. Cho. This work was supported by NSF DMR 9700767, and by QUEST, an NSF Science and Technology Center. Data for ML B were taken at the National High Magnetic Field Laboratory, which is supported by NSF Cooperative Agreement No. DMR-9527035 and by the state of Florida.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Electrical and Electronic Engineering