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arXiv · 1106.0089

Anomalous robustness of the 5/2 fractional quantum Hall state near a sharp phase boundary

Yang Liu·D. Kamburov·M. Shayegan·L. N. Pfeiffer·K. W. West·K. W. Baldwin
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Abstract

We report magneto-transport measurements in wide GaAs quantum wells with tunable density to probe the stability of the fractional quantum Hall effect at filling factor $ν= $ 5/2 in the vicinity of the crossing between Landau levels (LLs) belonging to the different (symmetric and antisymmetric) electric subbands. When the Fermi energy ($E_F$) lies in the excited-state LL of the symmetric subband, the 5/2 quantum Hall state is surprisingly stable and gets even stronger near this crossing, and then suddenly disappears and turns into a metallic state once $E_F$ moves to the ground-state LL of the antisymmetric subband. The sharpness of this disappearance suggests a first-order transition.

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Yang Liu, D. Kamburov, M. Shayegan, L. N. Pfeiffer, K. W. West, K. W. Baldwin. 2011-09-07. Anomalous robustness of the 5/2 fractional quantum Hall state near a sharp phase boundary. https://doi.org/10.1103/physrevlett.107.176805

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