Density and strain dependence of ν=1 energy gap in a valley-degenerate AlAs quantum well
Density and strain dependence of ν=1 energy gap in a valley-degenerate AlAs quantum well
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谷简并 AlAs 量子阱中 ν=1 能隙的密度和应变依赖性
DOI：
10.1103/physrevb.81.115336
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发表时间：
2010
影响因子：
3.7
通讯作者：
M. Shayegan
中科院分区：
文献类型：
--
作者：
T. Gokmen;M. Shayegan
在AlAs量子阱中，二维电子占据两个具有各向异性费米轮廓的导带谷，我们通过施加应变来调节谷分裂能量，并测量填充因子$\ensuremath{\nu}=1$的量子霍尔态的能隙。在零谷分裂能（应变），有一个相当大的能隙线性增加与密度。在固定密度下，差距随应变增加而增加的速度比单粒子图像预测的要快得多。解释的快速上升的差距作为一个签名的谷Skyrmions，我们发现，它们的大小随着电子密度的增加。
In an AlAs quantum well where two-dimensional electrons occupy two conduction-band valleys with anisotropic Fermi contours, we tune the valley splitting energy via the application of strain and measure the energy gaps for the quantum-Hall state at filling factor $\ensuremath{\nu}=1$. At zero valley splitting energy (strain), there is a sizeable energy gap which increases linearly with density. At a fixed density, the gap rises with increasing strain much faster than the single-particle picture predicts. Interpreting the rapid rise of the gap as a signature of valley Skyrmions, we find that their size grows as the electron density increases.