Transition-metal dichalcogenides for spintronic applications
Transition-metal dichalcogenides for spintronic applications
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DOI：
10.1002/andp.201400137
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发表时间：
2014-10-01
影响因子：
2.4
通讯作者：
Heine, Thomas
中科院分区：
文献类型：
--
作者：
Zibouche, Nourdine;Kuc, Agnieszka;Heine, Thomas
基于密度泛函理论，在二维周期性边界条件下研究了过渡金属二硫属化物单分子膜的自旋轨道分裂。自旋-轨道分裂达到几百meV，并随着金属和硫族元素原子的大小而增加，导致WTe 2接近500 meV。此外，我们发现，类似于带隙，自旋轨道分裂急剧变化的拉伸应变。在中心对称的过渡金属双硫族化合物双层膜中，自旋轨道分裂被反转对称性抑制。然而，如果反转对称性被明确破坏，例如通过垂直于平面的电势梯度，它可以被诱导，因为它存在于异质双层中（Rashba分裂）。在这样的系统中，自旋轨道分裂可能与形成异质双层的较重单层一样大。过渡金属二硫属化物材料的这些性质表明它们在光电子学、自旋电子学和应变电子学中具有潜在的应用。
Spin-orbit splitting in transition-metal dichalcogenide monolayers is investigated on the basis of density-functional theory within explicit two-dimensional periodic boundary conditions. The spin-orbit splitting reaches few hundred meV and increases with the size of the metal and chalcogen atoms, resulting in nearly 500 meV for WTe2. Furthermore, we find that similar to the band gap, spin-orbit splitting changes drastically under tensile strain. In centrosymmetric transition metal dichalcogenide bilayers, spin-orbit splitting is suppressed by the inversion symmetry. However, it could be induced if the inversion symmetry is explicitly broken, e.g. by a potential gradient normal to the plane, as it is present in heterobilayers (Rashba-splitting). In such systems, the spin-orbit splitting could be as large as for the heavier monolayer that forms heterobilayer. These properties of transition metal dichalcogenide materials suggest them for potential applications in opto-, spin- and straintronics.