Electronic structure of La (0001) thin films on W (110) studied by photoemission spectroscopy and first principle calculations
Electronic structure of La (0001) thin films on W (110) studied by photoemission spectroscopy and first principle calculations
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DOI：
10.1007/s11433-019-1501-8
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发表时间：
2020-02
期刊：
影响因子：
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通讯作者：
X. Ji;Qiuyun Chen;X. Lai;Li Huang;S. Tan
中科院分区：
文献类型：
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作者：
X. Ji;Qiuyun Chen;X. Lai;Li Huang;S. Tan
表面布里渊区(BZ)中心具有dz2对称性的表面态一直被认为是稀土金属紧密堆积表面的常见现象。在这项工作中，我们用超高能量分辨角度分辨光电子能谱(ARPES)和第一性原理计算研究了dhcp La(0001)薄膜的电子结构。我们的第一个原理分析是基于多体方法，因此，密度泛函理论(DFT)和动态平均场理论(DMFT)相结合。当密度泛函重整化因子在2-3之间时，实验观察到的费米表面拓扑结构和接近费米能量的能带结构与第一性原理计算结果定性一致。依赖于光子能量的ARPES测量显示，BZ中心周围的空穴带与Z有明显的相关性，以前被认为是表面态。ARPES结果和理论计算表明，dhcp La(0001)在费米能级附近的主要能带来源于体态La5dorbit，而不是表面态。
Surface states that have a dz2symmetry around the center of the surface Brillouin zone (BZ) have been regarded common in closely-packed surfaces of rare-earth metals. In this work, we report the electronic structure of dhcp La (0001) thin films by ultrahigh energy resolution angle-resolved photoemission spectroscopy (ARPES) and first principle calculations. Our first principle analysis is based on the many-body approach, therefore, density function theory (DFT) combined with dynamic mean-field theory (DMFT). The experimentally observed Fermi surface topology and band structure close to the Fermi energy qualitatively agree with first principle calculations when using a renormalization factor of between 2 and 3 for the DFT bands. Photon energy dependent ARPES measurements revealed clearkZdependence for the hole-like band around the BZ center, previously regarded as a surface state. The obtained ARPES results and theoretical calculations suggest that the major bands of dhcp La (0001) near the Fermi level originate from the bulk La5dorbits as opposed to originating from the surface states.