Giant spin-orbit-induced spin splitting in two-dimensional transition-metal dichalcogenide semiconductors
Giant spin-orbit-induced spin splitting in two-dimensional transition-metal dichalcogenide semiconductors
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DOI：
10.1103/physrevb.84.153402
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发表时间：
2011-10-14
影响因子：
3.7
通讯作者：
Schwingenschloegl, U.
中科院分区：
文献类型：
--
作者：
Zhu, Z. Y.;Cheng, Y. C.;Schwingenschloegl, U.
采用基于密度泛函理论的完全相对论第一性原理计算，研究了过渡金属二硫属元素MoS 2、MoSe 2、WS 2和WSe 2单层系统中自旋轨道诱导的自旋分裂。所有这些系统都被确定为直接带隙半导体。148-456 meV的巨大自旋分裂是由于缺少反转对称性。完全的面外自旋极化是由于电子运动的二维性质和电势梯度不对称性。通过抑制Dyakonov-Perel自旋弛豫，自旋寿命预计将非常长。由于这些材料具有巨大的自旋劈裂效应，因此在自旋电子学方面有着巨大的应用潜力。
Fully relativistic first-principles calculations based on density functional theory are performed to study the spin-orbit-induced spin splitting in monolayer systems of the transition-metal dichalcogenides MoS2, MoSe2, WS2, and WSe2. All these systems are identified as direct-band-gap semiconductors. Giant spin splittings of 148-456 meV result from missing inversion symmetry. Full out-of-plane spin polarization is due to the two-dimensional nature of the electron motion and the potential gradient asymmetry. By suppression of the Dyakonov-Perel spin relaxation, spin lifetimes are expected to be very long. Because of the giant spin splittings, the studied materials have great potential in spintronics applications.