Quasiparticle interference scattering of spin-polarized Shockley-like surface state electrons: Ni(111)
Quasiparticle interference scattering of spin-polarized Shockley-like surface state electrons: Ni(111)
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DOI：
10.1103/physrevb.89.155413
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发表时间：
2014-04-08
影响因子：
3.7
通讯作者：
Bode, Matthias
中科院分区：
文献类型：
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作者：
Kroenlein, Andreas;Kemmer, Jeannette;Bode, Matthias
我们报告了通过低温扫描隧道光谱（LT-STS）对Ni（111）表面进行的详细准粒子干涉（QPI）散射研究。虽然传统的常数分离STS显示了两个广泛的功能，这被解释为阿尔法3散装带和sp-样的肖克利型表面态（SP-SS），能量依赖的傅立叶变换的QPI地图揭示了底层表面电子功能的带色散。在sp-SS色散中，我们发现了两个类电子分支，它们被解释为交换分裂的少数和多数自旋部分。交换分裂被确定为Δ E-ex = 100 +/- 8 meV。此外，还发现了一个由d导出的类孔表面共振，在小k值下用抛物线拟合能带色散，确定了能带起始点和有效电子质量。杂化效应与体电子态观察到更大的k值。在空位岛内获得的STS数据中观察到了sp-SS的突出量子限制现象。结果可以用一维量子阱模型来解释。
We report on a detailed quasiparticle interference (QPI) scattering study of the Ni(111) surface by low-temperature scanning tunneling spectroscopy (LT-STS). While conventional constant-separation STS shows two broad features, which are interpreted as the Alpha 3 bulk band and sp-like Shockley-type surface state (sp-SS), energy-dependent Fourier-transformed QPI maps reveal the band dispersion of the underlying surface electronic features. We find two electronlike branches in the sp-SS dispersion, which are interpreted as the exchange-split minority and majority spin part. The exchange splitting is determined to Delta E-ex = 100 +/- 8 meV. In addition, a holelike d-derived surface resonance is found. Band onsets and effective electron masses are determined by fitting the band dispersion with a parabola at small k values. Hybridization effects with bulk electronic states are observed towards larger k values. Prominent quantum confinement phenomena of the sp-SS are observed in STS data obtained within vacancy islands. The results can be interpreted within a one- dimensional quantum-well model.