The effect of spin-orbit coupling on the electronic properties of monolayer (ML) ${\mathrm{PtSe}}_2$ is dictated by the presence of the crystal inversion symmetry to exhibit a spin-polarized band without the characteristic of spin splitting. Through fully relativistic density-functional theory calculations, we show that large spin-orbit splitting can be induced by introducing point defects. We calculate the stability of native point defects such as a Se vacancy (${\mathrm{V}}_{\text{Se}}$), a Se interstitial (${\mathrm{Se}}_i$), a Pt vacancy (${\mathrm{V}}_{\text{Pt}}$), and a Pt interstitial (${\mathrm{Pt}}_i$) and find that both the ${\mathrm{V}}_{\text{Se}}$ and ${\mathrm{Se}}_i$ have the lowest formation energy. We also find that, in contrast to the ${\mathrm{Se}}_i$ case exhibiting spin degeneracy in the defect states, the large spin-orbit splitting up to 152 meV is observed in the defect states of the ${\mathrm{V}}_{\text{Se}}$. Our analyses of orbital contributions to the defect states show that the large spin splitting is originated from the strong hybridization between Pt-$d_{x{}^2+y{}^2}+d_{xy}$ and Se-$p_x+p_y$ orbitals. Our study clarifies that the defects play an important role in the spin-splitting properties of the ${\mathrm{PtSe}}_2$ ML, which is important for designing future spintronic devices.

中文翻译：

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缺陷诱导的单层PtSe2大自旋轨道分裂

自旋轨道耦合对单层电子特性的影响 ${\mathrm{铂硒}}_{\mathrm{2个}}$晶体反转对称性的存在决定了其具有自旋极化带而没有自旋分裂的特征。通过完全相对论的密度泛函理论计算，我们表明可以通过引入点缺陷来诱发大的自旋轨道分裂。我们计算诸如Se空位（${\mathrm{伏特}}_{\text{硒}}$），Se插页式广告（${硒}_{\mathrm{一世}}$），Pt空缺（${\mathrm{伏特}}_{\text{铂}}$）和Pt插页式广告（${铂}_{\mathrm{一世}}$），然后发现 ${\mathrm{伏特}}_{\text{硒}}$ 和 ${硒}_{\mathrm{一世}}$具有最低的编队能量。我们还发现，与${硒}_{\mathrm{一世}}$ 在缺陷状态下表现出自旋简并性的情况下，在缺陷状态下观察到高达152 meV的大自旋轨道分裂。 ${\mathrm{伏特}}_{\text{硒}}$。我们对缺陷态轨道贡献的分析表明，大的自旋分裂是由Pt-$d_{X{}^{\mathrm{2个}}+ÿ{}^{\mathrm{2个}}}+d_{Xÿ}$ 和硒$p_X+p_{ÿ}$轨道。我们的研究表明，缺陷在合金的自旋分裂特性中起着重要作用。${\mathrm{铂硒}}_{\mathrm{2个}}$ ML，对于设计未来的自旋电子器件很重要。