Coexistence of two types of spin splitting originating from different symmetries
Coexistence of two types of spin splitting originating from different symmetries
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源自不同对称性的两种自旋分裂的共存
DOI：
10.1103/physrevlett.122.126403
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发表时间：
2019
影响因子：
8.6
通讯作者：
Fumio Komori and Shik Shin
中科院分区：
文献类型：
--
作者：
Koichiro Yaji;Anton Visikovskiy;Takushi Iimori;Kenta Kuroda;Singo Hayashi;Takashi Kajiwara;Satoru Tanaka;Fumio Komori and Shik Shin
表面或界面的对称性在确定二维能带的自旋分裂和织构方面起着重要作用。通过自旋和角分辨光电子能谱研究了 SiC(0001) 衬底上由 Sn 组成的三角形晶格原子层 (TLAL) 的自旋偏振带。令人惊讶的是，塞曼型和拉什巴型自旋分裂带（分别不具有自旋简并性和具有自旋简并性）共存于 Sn TLAL 的一点上。根据包括SiC周期性在内的晶体结构，该点具有三重对称性，没有反演对称性，这意味着塞曼型与晶格的对称性一致，而拉什巴型则不一致。我们的密度泛函计算表明，Rashba 型（塞曼型）带的电荷密度分布在该点表现出（无）反演对称性。因此，电荷密度分布的对称性与两种类型的自旋分裂一致。
The symmetry of a surface or interface plays an important role in determining the spin splitting and texture of a two-dimensional band. Spin-polarized bands of a triangular lattice atomic layer (TLAL) consisting of Sn on a SiC(0001) substrate is investigated by spin- and angle-resolved photoelectron spectroscopy. Surprisingly, both Zeeman- and Rashba-type spin-split bands, without and with spin degeneracy, respectively, coexist at apoint of the Sn TLAL. Thepoint has a threefold symmetry without inversion symmetry according to the crystal structure including the SiC periodicity, meaning that the Zeeman-type is consistent with the symmetry of the lattice while the Rashba-type is inconsistent. Our density functional calculations reveal that the charge density distribution of the Rashba-type (Zeeman-type) band shows (no) inversion symmetry at thepoint. Therefore, the symmetry of the charge density distribution agrees with both types of the spin splitting.