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arXiv · 2210.11827

A possible electronic state quasi-half-valley-metal in $\mathrm{VGe_2P_4}$ monolayer

San-Dong Guo·Yu-Ling Tao·Zhuo-Yan Zhao·Bing Wang·Guangzhao Wang·Xiaotian Wang
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Abstract

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.

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San-Dong Guo, Yu-Ling Tao, Zhuo-Yan Zhao, Bing Wang, Guangzhao Wang, Xiaotian Wang. 2022-10-21. A possible electronic state quasi-half-valley-metal in $\mathrm{VGe_2P_4}$ monolayer. https://doi.org/10.1103/physrevb.107.054414

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