Realization of In0.75Ga0.25As two-dimensional electron gas bilayer system for spintronics devices based on Rashba spin-orbit interaction
Realization of In0.75Ga0.25As two-dimensional electron gas bilayer system for spintronics devices based on Rashba spin-orbit interaction
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DOI：
10.1063/1.4766749
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发表时间：
2012-12
影响因子：
3.2
通讯作者：
M. Akabori;S. Hidaka;H. Iwase;S. Yamada;U. Ekenberg
中科院分区：
文献类型：
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作者：
M. Akabori;S. Hidaka;H. Iwase;S. Yamada;U. Ekenberg
制备了窄间隙InGaAs二维电子气（2DEG）双层样品，并证实其具有良好的电子质量和较强的Rashba型自旋轨道相互作用（SOI）。通过分子束外延以宽量子威尔斯（QW）的形式实现2DEG系统，其中厚度tQW为40-120 nm，调制掺杂在上部和下部InAlAs势垒中。从霍尔测量中，总的迁移率值μe为15 m2/V s，总的片状电子密度为ns = 18 × 1011/cm 2，尽管ns在上、下2DEG中的分布不对称，分别约为1：3。仔细的低温磁阻分析给出了大的SO耦合常数α = 20 × 10−12 eV m，以及每个双层2DEG自旋子带的预期电子有效质量m*/m0 = 0.033-0.042。此外，还发现α随tQW的减小而增强，并进行了相应的自洽计算，表明双层2DEG之间存在相互作用。
Narrow gap InGaAs two-dimensional electron gas (2DEG) bilayer samples are fabricated and confirmed to have good electronic qualities as well as strong Rashba-type spin-orbit interactions (SOIs). The 2DEG systems are realized by molecular beam epitaxy in the form of wide quantum wells (QWs) with thicknesses tQW ∼ 40–120 nm modulation doped in both the upper and lower InAlAs barriers. From the Hall measurements, the overall mobility values of μe ∼15 m2/V s are found for the total sheet electron density of ns ∼8 × 1011/cm2, although the ns is distributed asymmetrically as about 1:3 in the upper and lower 2DEGs, respectively. Careful low temperature magneto-resistance analysis gives large SO coupling constants of α ∼20 × 10−12 eV m as well as expected electron effective masses of m*/m0 ∼0.033-0.042 for each bilayer 2DEG spin sub-band. Moreover, the enhancement of α with decrease of tQW is found. The corresponding self-consistent calculation, which suggests the interaction between the bilayer 2DEGs, is carried...