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arXiv · 1405.6188

Competing quantum Hall phases in the second Landau level in low density limit

W. Pan·A. Serafin·J. S. Xia·L. Yin·N. S. Sullivan·K. W. Baldwin·K. W. West·L. N. Pfeiffer·D. C. Tsui
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Abstract

We present in this Letter the results from two high quality, low density GaAs quantum wells. In sample A of electron density n=5.0x10^10 cm^-2, anisotropic electronic transport behavior was observed at \nu=7/2 in the second Landau level. We believe that the anisotropy is due to the large Landau level mixing effect in this sample. In sample B of density 4.1x10^10 cm^-2, strong 8/3, 5/2, and 7/3 fractional quantum Hall states were observed. Furthermore, our energy gap data suggest that, similar to the 8/3 state, the 5/2 state may also be spin unpolarized in the low density limit. The results from both samples show that the strong electron-electron interactions and a large Landau level mixing effect play an import role in the competing ground states in the second landau level.

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W. Pan, A. Serafin, J. S. Xia, L. Yin, N. S. Sullivan, K. W. Baldwin, K. W. West, L. N. Pfeiffer, D. C. Tsui. 2014-05-23. Competing quantum Hall phases in the second Landau level in low density limit. https://doi.org/10.1103/physrevb.89.241302

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