Competing quantum Hall phases in the second Landau level in the low-density limit
Competing quantum Hall phases in the second Landau level in the low-density limit
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DOI：
10.1103/physrevb.89.241302
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发表时间：
2014-06-09
影响因子：
3.7
通讯作者：
Tsui, D. C.
中科院分区：
文献类型：
--
作者：
Pan, W.;Serafin, A.;Tsui, D. C.
在这篇文章中，我们介绍了两个高质量、低密度GaAs量子威尔斯阱的结果。在电子密度n = 5.0 × 10（10）cm（-2）的样品A中，在第二朗道能级nu = 7/2处观察到各向异性的电子输运行为。我们认为，各向异性是由于在这个样品中的大的朗道能级混合效应。在密度为4.1 × 10（10）cm（-2）的样品B中，观察到强的8/3、5/2和7/3分数量子霍尔态。此外，我们的能隙数据表明，类似于8/3状态，5/2状态也可能是自旋非极化的低密度极限。结果表明，强的电子-电子相互作用和大的朗道能级混合效应对第二朗道能级的基态竞争起着重要作用.
In this Rapid Communication we present the results from two high-quality, low-density GaAs quantum wells. In sample A of electron density n = 5.0 x 10(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 4.1 x 10(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.