论文标题
$ \ mathrm {vge_2p_4} $ monolayer的可能的电子状态准半瓦利 - 金属
A possible electronic state quasi-half-valley-metal in $\mathrm{VGe_2P_4}$ monolayer
论文作者
论文摘要
Valleytronics的关键问题之一是实现山谷两极分化。已经提出了Ferrovalley（FV）半导体和半谷基 - 金属（HVM），它们具有内在的自发山谷极化。在这里，我们提出了准半瓦利 - 金属（QHVM）的概念，包括电子和孔载体，其中只有一种载体是山谷两极化的。 QHVM可以实现电子和孔的分离函数。 $ \ mathrm {VGE_2P_4} $单层的具体示例用于通过第一原则计算来说明我们的建议。为了更好地实现QHVM，电场应用于$ \ mathrm {vge_2p_4} $的调子相关谷地。在被考虑的电场范围内，$ \ mathrm {VGE_2P_4} $始终是Ferromagnetic（FM）基态，它通过计算磁各向异性能量（MAE）（包括磁性异型型（MSA）和磁晶型矛盾的型磁性异位型（MCA），它具有平面外磁化。这些平面外FM属性保证了$ \ Mathrm {VGE_2P_4} $中内在的自发谷极化。在一定范围内的电场范围内，可以维持QHVM，并且可以有效地调整相关的极化特性。我们的作品为valleytronics的二维（2D）功能材料设计铺平了道路。
One of the key problems in valleytronics is to realize valley polarization. Ferrovalley (FV) semiconductor and half-valley-metal (HVM) have been proposed, which possess intrinsic spontaneous valley polarization. Here, we propose the concept of quasi-half-valley-metal (QHVM), including electron and hole carriers with only a type of carriers being valley polarized. The QHVM may realize separation function of electron and hole. A concrete example of $\mathrm{VGe_2P_4}$ monolayer is used to illustrate our proposal through the first-principle calculations. To better realize QHVM, the electric field is applied to tune related valley properties of $\mathrm{VGe_2P_4}$. Within considered electric field range, $\mathrm{VGe_2P_4}$ is always ferromagnetic (FM) ground state, which possesses out-of-plane magnetization by calculating magnetic anisotropy energy (MAE) including magnetic shape anisotropy (MSA) and magnetocrystalline anisotropy (MCA) energies. These out-of-plane FM properties guarantee intrinsic spontaneous valley polarization in $\mathrm{VGe_2P_4}$. Within a certain range of electric field, the QHVM can be maintained, and the related polarization properties can be effectively tuned. Our works pave the way toward two-dimensional (2D) functional materials design of valleytronics.
