Structure determination of Pb/Ge(111)-β-(√3×√3) R30° by dynamical low-energy electron diffraction analysis and first-principles calculation
Structure determination of Pb/Ge(111)-β-(√3×√3) R30° by dynamical low-energy electron diffraction analysis and first-principles calculation
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动态低能电子衍射分析和第一性原理计算确定Pb/Ge(111)-β-(√3×√3) R30°的结构
DOI：
10.1088/0953-8984/23/43/435001
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Tetsuya Aruga
中科院分区：
文献类型：
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作者：
Yoshiyuki Ohtsubo;Hiroshi Muto;Koichiro Yaji;Shinichiro Hatta;Hiroshi Okuyama;Tetsuya Aruga
我们测定了Pb/Ge (111)-β(√3 x√3)r300表面的原子结构，并通过动态低能电子衍射分析证明其在金属表面态表现出较大的Rashba自旋分裂。优化后的原子结构的Pb覆盖率为4/3，其中1个Pb原子位于体积截短的Ge（111）表面的每3个H3位上，另外3个Pb原子位于T1位附近，但向T4位略微偏移。所确定的原子结构与第一性原理计算得到的能量优化结构吻合得很好。计算还表明，H3位上Pb原子的电位沿表面法向非常软，表明它们的垂直位置分布在0.2 ~ 0.3 a的范围内。讨论了先前提出的与表面熔化有关的相变。(纸)
We have determined the atomic structure of the Pb/Ge (111)-β (√ 3 x√ 3) R30o surface, which was shown to exhibit a large Rashba spin splitting in a metallic surface state by dynamical low-energy electron diffraction analysis. The Pb coverage for the optimized atomic structure is 4/3 with one Pb atom located at every third H3 site of the bulk-truncated Ge (111) surface and the other three near the T1 sites but slightly displaced towards the T4 sites. The determined atomic structure agrees well with the energetically optimized one obtained from the first-principles calculation. The calculation also revealed that the potential for the Pb atoms on the H3 sites is very soft along the surface normal, suggesting that their vertical position is distributed within a range of about 0.2-0.3 A. The previously proposed phase transition associated with the surface melting is discussed.(paper)