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Manifestation of the Exchange Enhancement of the Valley Splitting in the Quantum Hall Effect Regime

I. Shlimak·V. Ginodman·K. -J. Friedland·S. V. Kravchenko
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Abstract

We report a new "dip" effect in the Hall resistance, R_{xy}, of a Si metal-oxide-semiconductor field-effect transistor in the quantum Hall effect regime. With increasing magnetic field, the Hall resistance moves from the plateau at Landau filling factor ν=6 directly to the plateau at ν=4, skipping the plateau at ν=5. However, when the filling factor approaches ν=5, the Hall resistance sharply "dives" to the value 1/5(h/e^2) characteristic of the ν=5 plateau, and then returns to 1/4(h/e^2). This is interpreted as a manifestation of the oscillating exchange enhancement of the valley splitting when the Fermi level is in the middle between two adjacent valley-split Landau bands with the asymmetric position of the extended states.

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I. Shlimak, V. Ginodman, K. -J. Friedland, S. V. Kravchenko. 2006-02-16. Manifestation of the Exchange Enhancement of the Valley Splitting in the Quantum Hall Effect Regime. https://doi.org/10.1103/physrevb.73.205324

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