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arXiv · 1110.4280

Topological quantum number and critical exponent from conductance fluctuations at the quantum Hall plateau transition

I. C. Fulga·F. Hassler·A. R. Akhmerov·C. W. J. Beenakker
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Abstract

The conductance of a two-dimensional electron gas at the transition from one quantum Hall plateau to the next has sample-specific fluctuations as a function of magnetic field and Fermi energy. Here we identify a universal feature of these mesoscopic fluctuations in a Corbino geometry: The amplitude of the magnetoconductance oscillations has an e^2/h resonance in the transition region, signaling a change in the topological quantum number of the insulating bulk. This resonance provides a signed scaling variable for the critical exponent of the phase transition (distinct from existing positive definite scaling variables).

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I. C. Fulga, F. Hassler, A. R. Akhmerov, C. W. J. Beenakker. 2011-10-20. Topological quantum number and critical exponent from conductance fluctuations at the quantum Hall plateau transition. https://doi.org/10.1103/physrevb.84.245447

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