School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, China.
J Chem Phys. 2019 Feb 14;150(6):064701. doi: 10.1063/1.5064759.
Two-dimensional SnSe has become more and more attractive due to the excellent electronic, optoelectronic, and thermoelectric properties. However, the study on magnetic properties is rare. Inspired by the recent experimental synthesis of SnSe monolayer and Ag-doped SnSe thin films, we use the first-principles calculations combined with the nonequilibrium Green's function method to investigate the structural, electronic, magnetic, and spin transport properties of an Ag-doped SnSe monolayer. It is found that the doped system exhibits half-metallic ferromagnetism with the energy gap of about 0.5 eV in the spin-down channel. The spin-polarized transport properties based on Ag-doped SnSe monolayers show an excellent spin filtering effect and a negative differential resistance effect under a bias voltage. Interestingly, under a temperature gradient, the spin Seebeck effect and the temperature-controlled reverse of spin polarization are also observed. These perfect spin transport properties can be understood from the calculated spin-polarized band structure and the spin-polarized transport spectrum. These studies indicate the potential spintronic and spin caloritronic applications for Ag-doped SnSe monolayer.
二维的 SnSe 由于其优异的电子、光电和热电性能而变得越来越有吸引力。然而，对其磁性的研究却很少。受最近实验合成的 SnSe 单层和掺 Ag 的 SnSe 薄膜的启发，我们使用第一性原理计算结合非平衡格林函数方法来研究掺 Ag 的 SnSe 单层的结构、电子、磁和自旋输运性质。结果发现，掺杂体系在自旋向下通道中表现出约 0.5eV 的能隙的半金属铁磁性。基于掺 Ag 的 SnSe 单层的自旋极化输运性质在偏压下表现出优异的自旋过滤效应和负微分电阻效应。有趣的是，在温度梯度下，还观察到自旋 Seebeck 效应和自旋极化的温度控制反转。这些完美的自旋输运性质可以从计算得到的自旋极化能带结构和自旋极化输运谱中得到理解。这些研究表明掺 Ag 的 SnSe 单层在自旋电子学和自旋热电子学方面具有潜在的应用。
