Thickness dependence of spin polarization and electronic structure of ultra-thin films of MoS2 and related transition-metal dichalcogenides.
Thickness dependence of spin polarization and electronic structure of ultra-thin films of MoS2 and related transition-metal dichalcogenides.
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MOS2的超薄膜和相关过渡金属二核苷的超薄膜的自旋极化和电子结构的厚度依赖性。
DOI：
10.1038/srep06270
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发表时间：
2014-09-05
影响因子：
4.6
通讯作者：
Bansil A
中科院分区：
文献类型：
--
作者：
Chang TR;Lin H;Jeng HT;Bansil A
我们对过渡金属二硫族化合物MX2（M = Mo或W; X = S，Se或Te）超薄膜进行了与厚度相关的第一性原理电子结构计算。当计算中包括自旋轨道耦合（SOC）时，单层MX2薄膜在布里渊区拐角处的价带最大值附近显示自旋分裂态，自旋极化率接近100%。自旋在K和K′点处沿沿着面外方向相反地排列。对于双层膜，自旋极化的SOC诱导带分裂可以打开或关闭的平面外的外部电场。在具有小kz色散的体MX2化合物中，自旋极化态在层之间弱耦合。我们确认从间接到直接带隙的过渡，厚度减少到单层的二硫化钼，与最近的实验结果一致。由于MX2化合物具有较大的自旋分裂能和绝缘带隙，因此在室温下具有很大的自旋/谷电子应用潜力。
We have carried out thickness dependent first-principles electronic structure calculations on ultra-thin films of transition-metal dichalcogenides MX2 (M = Mo or W; X = S, Se, or Te). When spin-orbit coupling (SOC) is included in the computations, monolayer MX2 thin films display spin-split states around the valence band maximum at the Brillouin zone corners with nearly 100% spin polarization. The spins are aligned oppositely along out-of-the-plane direction at the K and K′ points. For the bilayer films, spin polarization of this SOC induced band splitting can be switched on or off by an out-of-the-plane external electric field. The spin-polarized states are weakly coupled between the layers in bulk MX2 compounds with small kz dispersion. We confirm a transition from an indirect to direct band gap as the thickness is reduced to a monolayer in MoS2, in agreement with recent experimental findings. Owing to the presence of a large spin-splitting energy and an insulating band gap, MX2 compounds have great potential for spin/valley electronic applications at room temperature.
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影响因子：
56.9
作者：
Bernevig, B. Andrei;Hughes, Taylor L.;Zhang, Shou-Cheng
通讯作者：
Zhang, Shou-Cheng
影响因子：
56.9
作者：
Koenig, Markus;Wiedmann, Steffen;Zhang, Shou-Cheng
通讯作者：
Zhang, Shou-Cheng
影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J
DOI：
10.1088/0022-3719/5/7/007
发表时间：
1972-01-01
期刊：
JOURNAL OF PHYSICS PART C SOLID STATE PHYSICS
影响因子：
--
作者：
BROMLEY, RA;YOFFE, AD;MURRAY, RB
通讯作者：
MURRAY, RB
影响因子：
2.1
作者：
Bolotin, K. I.;Sikes, K. J.;Stormer, H. L.
通讯作者：
Stormer, H. L.