Exact quantization of the even-denominator fractional quantum Hall state at v=5/2 Landau level filling factor
Exact quantization of the even-denominator fractional quantum Hall state at v=5/2 Landau level filling factor
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DOI：
10.1103/physrevlett.83.3530
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发表时间：
1999-10-25
影响因子：
8.6
通讯作者：
West, KW
中科院分区：
文献类型：
--
作者：
Pan, W;Xia, JS;West, KW
本文报道了在超低温下，在朗道能级填充因子nu = 5/2，μ = 1.7 × 10（7）cm（2）/V s的超高迁移率样品中观察到的分数量子霍尔效应。我们实现了电子温度低至4 mK，在那里我们观察到消失的R-xx和。第一次将量子化霍尔电阻R-xy = h/（5/2）e（2）精确到2 ppm以内。相邻奇分母状态nu = 7/3和8/3处的R-xv也被量化。在这些分数填充处的R1最小值的温度依赖性产生激活能隙Δ（5/2）= 0.11、Δ（7/3）= 0.10和Δ（8/3）= 0.055 K。
We report ultralow temperature experiments on the obscure fractional quantum Hall effect at Landau level filling factor nu = 5/2 in a very high-mobility specimen of mu = 1.7 X 10(7) cm(2)/V s. We achieve an electron temperature as low as similar to 4 mK, where we observe vanishing R-xx and. for the first time, a quantized Hall resistance, R-xy = h/(5/2)e(2) to within 2 ppm. R-xv at the neighboring odd-denominator states nu = 7/3 and 8/3 is also quantized. The temperature dependences of the R, minima at these fractional fillings yield activation energy gaps Delta(5/2) = 0.11, Delta(7/3) = 0.10, and Delta(8/3) = 0.055 K.