Theoretical investigation of electronic transport in functionalized 2D transition metal dichalcogenides

过渡金属二卤化物(TMD)单分子膜是一种很有前途的超薄材料，通过提供具有强自旋-轨道耦合的可调谐金属相，有望完善石墨烯相关材料的范围。其中许多TMD可以通过小的结构变形和掺杂第6族TMD来实现，因此可以用作电极材料，从而在单分子层内形成非常低的接触电阻。金属TMD的实验研究很困难，因为这些相通常是亚稳态的，或者依赖于非常微妙的结构修改。因此，在进行复杂的实验研究之前，必须进行仔细的理论研究。该联盟将研究金属TMD结构，包括本征金属相、亚稳态金属相以及引发半导体-金属转变的外部因素，如掺杂、缺陷和应变。将特别注意自旋-轨道分裂以及控制它们的方法。计算机模拟的范围从小单胞的能带结构计算到相当复杂的系统，包括异质结构、掺杂和缺陷系统直到晶界。关于这些材料在实际应用中的适用性的结论将通过显式输运计算和器件模拟进一步得到证实。虽然大多数计算可以使用最先进的软件进行，但一些方法的开发是必要的，并将在这里进行。通过使用电导率张量分量的多项式展开，将开发出与系统大小O(N)成线性比例的数值方法。这将允许在无序存在的情况下模拟大的单胞，并计算与自旋和山谷相关的贡献。因此，用真实的TMD模型来描述自旋和谷霍尔效应是合适的。除了金属TMD之外，我们还将研究将半导体TMD功能化应用于自旋电子学的可能性。创造稀磁半导体的二维等价物的可能性将对自旋电子学的研究产生重大影响。通过掺杂磁性过渡金属，我们将研究诱导可调谐磁性相变的可能性。同样，我们将模拟2D材料与铁磁接触的耦合，并研究无序和自旋轨道相互作用对自旋电子器件中此类接触性能的影响。该联盟将与旗舰石墨烯核心项目的各个成员保持良好的关系。

Metallic transition metal dichalcogenide (TMD) monolayers are promising ultrathin materials which have the potential to complete the range of graphene-related materials by offering tunable metallic phases with strong spin-orbit coupling. Many of them can be achieved by small structural deformations and doping of Group 6 TMDs and thus could thus be used as electrode materialswithin a single monolayer, resulting in a very low contact resistance. Experimental study of metallic TMDs is difficult as these phases are often metastable or rely on very subtle structural modifications. Thus, a careful theoretical investigation is imperative before complex experimental studies should be pursued. This consortium will investigate metallic TMD structures, including intrinsically metallic phases, metastable metallic phases, and external factors to trigger semiconductor-metal transitions such as doping, defects and strain. Special attention will be given to spin-orbit splitting and ways to controlthem. Computer simulations will range from band-structure calculations of small unit cells to rather complex systems, including heterostructures, doped and defected systems up to grain boundaries. Conclusions on the suitability of these materials in practical application will be further confirmed byexplicit transport calculations and device simulations. While most calculations can be carried out using state-of-the-art software, some method developments are necessary and will be carried out here. Numerical methods that scale linearly with the system size, O(N), will be developed by using a polynomial expansion of the components of the conductivity tensor. These will allow for simulations of large unit cells in the presence of disorder and the calculation of spin- and valley- dependent contributions. It will become therefore suitable to describe the Spin and Valley Hall effects in realistic models of TMDs.Besides metallic TMDs we will also investigate the possibility of functionalizing semiconducting TMDs for spintronics applications. The possibility of creating the two-dimensional equivalent of the dilute magnetic semiconductor will have a strong impact on spintronics research. By doping with magnetic transition metals, we will investigate the possibility of inducing a tunable magnetic phase transition. On a similar note, we will model the coupling of 2D materials with ferromagnetic contacts and study the effect of disorder and spin-orbit interactions on the performance of such contacts in spintronic devices.The consortium will maintain its excellent relationship to various members of the FLAGSHIP Graphene core project.