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arXiv · 1302.1444

Observation of an anomalous density-dependent energy gap of the $ν=5/2$ fractional quantum Hall state in the low density regime

N. Samkharadze·Dohyung Ro·L. N. Pfeiffer·K. W. West·G. A. Csáthy
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Abstract

We have studied the $ν=5/2$ fractional quantum Hall state in a density-tunable sample at extremely low electron densities. For the densities accessed in our experiment, the Landau level mixing parameter $κ$ spans the $2.52<κ<2.82$ range. In the vicinity of $5.8 \times 10^{10}$~cm$^{-2}$ or $κ= 2.6$ an anomalously large change in the density dependence of the energy gap is observed. Possible origins of such an anomaly are discussed, including a topological phase transition in the $ν=5/2$ fractional quantum Hall state.

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N. Samkharadze, Dohyung Ro, L. N. Pfeiffer, K. W. West, G. A. Csáthy. 2017-08-07. Observation of an anomalous density-dependent energy gap of the $ν=5/2$ fractional quantum Hall state in the low density regime. https://doi.org/10.1103/physrevb.96.085105

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