Tunable Rashba Effect in Two-Dimensional LaOBiS2 Films: Ultrathin Candidates for Spin Field Effect Transistors
Tunable Rashba Effect in Two-Dimensional LaOBiS2 Films: Ultrathin Candidates for Spin Field Effect Transistors
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DOI：
10.1021/nl4027346
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发表时间：
2013-11-01
期刊：
影响因子：
10.8
通讯作者：
Freeman, Arthur J.
中科院分区：
文献类型：
--
作者：
Liu, Qihang;Guo, Yuzheng;Freeman, Arthur J.
Rashba自旋分裂是一种与自旋电子学密切相关的二维相对论效应。然而，到目前为止，还没有原始的2D材料表现出足够的Rashba分裂用于制造自旋电子器件，如自旋场效应晶体管（SFET）。第一性原理计算的基础上，我们预测，稳定的二维LaOBiS 2只有1 nm的厚度可以产生显着的Rashba自旋分裂的幅度为100 meV。由于介质La 2 O2层产生强极性场并作为阻挡层，两个反螺旋Rashba自旋极化被定位在不同的BiS 2层。内禀应变可以有效地调节Rashba参数，而带隙和自旋态的螺旋方向敏感地依赖于外电场。我们提出了一种先进的Datta-Das SFET模型，该模型由双栅极和2D LaOBiS 2沟道组成，通过选择不同的Rashba状态来实现通过电场的开关。
Rashba spin splitting is a two-dimensional (2D) relativistic effect closely related to spintronics. However, so far there is no pristine 2D material to exhibit enough Rashba splitting for the fabrication of ultrathin spintronic devices, such as spin field effect transistors (SFET). On the basis of first-principles calculations, we predict that the stable 2D LaOBiS2 with only 1 nm of thickness can produce remarkable Rashba spin splitting with a magnitude of 100 meV. Because the medium La2O2 layer produces a strong polar field and acts as a blocking bather, two counter-helical Rashba spin polarizations are localized at different BiS2 layers. The Rashba parameter can be effectively tuned by the intrinsic strain, while the bandgap and the helical direction of spin states sensitively depends on the external electric field. We propose an advanced Datta-Das SFET model that consists of dual gates and 2D LaOBiS2 channels by selecting different Rashba states to achieve the on-off switch via electric fields.