Zhao Pei, Li Jianwei, Jin Hao, Yu Lin, Huang Baibiao, Ying Dai
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.
Phys Chem Chem Phys. 2018 Apr 18;20(15):10286-10291. doi: 10.1039/c8cp00557e.
Giant tunnel magnetoresistance (TMR) and perfect spin-injection efficiency (SIE) are extremely significant for modern spintronic devices. Quantum transport properties in a two-dimensional (2D) VS2/MoS2/VS2 magnetic tunneling junction (MTJ) are investigated theoretically within the framework of density functional theory combining with the non-equilibrium Green's functions (DFT-NEGF) method. Our results indicate that the designed MTJ exhibits a TMR with a value up to 4 × 103, which can be used as a switch of spin-electron devices. And due to the huge barrier for spin-down transport, the spin-down electrons could hardly cross the central scattering region, thus achieving a perfect SIE. Furthermore, we also explore for the effect of bias voltage on the TMR and SIE. We find that the TMR increases with the increasing bias voltage, and the SIE is robust against either bias or gate voltage in MTJs, which can serve as effective spin filter devices. Our results can not only give fresh impetus to the research community to build MTJs but also provide potential materials for spintronic devices.
巨隧穿磁电阻（TMR）和完美的自旋注入效率（SIE）对于现代自旋电子器件极为重要。在密度泛函理论结合非平衡格林函数（DFT-NEGF）方法的框架内，从理论上研究了二维（2D）VS2/MoS2/VS2磁隧道结（MTJ）中的量子输运性质。我们的结果表明，所设计的MTJ展现出高达4×103的TMR值，可作为自旋电子器件的开关。并且由于自旋向下输运的巨大势垒，自旋向下的电子几乎无法穿过中心散射区域，从而实现了完美的SIE。此外，我们还探究了偏置电压对TMR和SIE的影响。我们发现TMR随偏置电压的增加而增大，并且MTJ中的SIE对偏置电压或栅极电压均具有鲁棒性，可作为有效的自旋过滤器件。我们的结果不仅能为研究团体构建MTJ提供新的动力，还能为自旋电子器件提供潜在材料。
