High temperature resistivity measured at �� = 5/2 as a predictor of 2DEG quality in the N=1 Landau level
| Autor: | Qian, Qi, Nakamura, James R., Fallahi, Saeed, Gardner, Geoffrey C., Watson, John D., Manfra, Michael J. |
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| Rok vydání: | 2017 |
| Předmět: | |
| DOI: | 10.48550/arxiv.1704.03794 |
| Popis: | We report a high temperature (T = 0.3K) indicator of the excitation gap $��_{5/2}$ at the filling factor $ ��=5/2$ fractional quantum Hall state in ultra-high quality AlGaAs/GaAs two-dimensional electron gases. As the lack of correlation between mobility $��$ and $��_{5/2}$ has been well established in previous experiments, we define, analyze and discuss the utility of a different metric $��_{5/2}$, the resistivity at $��=5/2$, as a high temperature predictor of $��_{5/2}$. This high-field resistivity reflects the scattering rate of composite fermions. Good correlation between $��_{5/2}$ and $��_{5/2}$ is observed in both a density tunable device and in a series of identically structured wafers with similar density but vastly different mobility. This correlation can be explained by the fact that both $��_{5/2}$ and $��_{5/2}$ are sensitive to long-range disorder from remote impurities, while $��$ is sensitive primarily to disorder localized near the quantum well. 11 pages, 4 figures |
| Databáze: | OpenAIRE |
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