Topologically stable bimerons and skyrmions in vanadium dichalcogenide Janus monolayers

Structural, electronic, and magnetic properties of Vanadium-based Janus dichalcogenide monolayers: A first-principles study

The structural, electronic, and magnetic properties of VSSe, VSeTe, VSTe monolayers in both 2H and 1T phases are investigated via first-principles calculations. The 2H phase is energetically favorable in VSSe and VSeTe, whereas the 1T phase is lower in energy in VSTe. For V-based Janus monolayers in the 2H phase, calculations of the magnetic anisotropy show an easy-plane for the magnetic moment. As such, they should not exhibit a ferromagnetic phase transition, but instead, a Berezinskii-Kosterlitz-Thouless (BKT) transition. A classical XY model with nearest-neighbor coupling estimates critica…

High-Temperature Ferromagnetic Semiconductors: Janus Monolayer Vanadium Trihalides

Two-dimensional (2D) intrinsic ferromagnetic semiconductors are expected to stand out in the spintronic field. Recently, the monolayer VI$_{3}$ has been experimentally synthesized but the weak ferromagnetism and low Curie temperature ($T_C$) limit its potential application. Here we report that the Janus structure can elevate the $T_C$ to 240 K. And it is discussed that the reason for high $T_C$ in Janus structure originates from the lower virtual exchange gap between $t_{2g}$ and $e_{g}$ states of nearest-neighbor V atoms. Besides, $T_C$ can be further substantially enhanced by tensile strain …

单层钒二硫族化合物中由 Janus 结构引入的异常电荷密度波

Unusual charge density wave introduced by Janus structure in monolayer vanadium dichalcogenides

该研究通过 VTe2 表面硒化制备单层 Janus VTeSe，利用扫描隧道显微镜和理论计算发现具有三重旋转对称性破缺的异常 √13×√13 CDW 态，其源于电荷调制而非传统电子—声子耦合。

Janus Monolayers of Magnetic Transition Metal Dichalcogenides as an All-in-One Platform for Spin-Orbit Torque

We theoretically predict that vanadium-based Janus dichalcogenide monolayers constitute an ideal platform for spin-orbit-torque memories. Using first principles calculations, we demonstrate that magnetic exchange and magnetic anisotropy energies are higher for heavier chalcogen atoms, while the broken inversion symmetry in the Janus form leads to the emergence of Rashba-like spin-orbit coupling. The spin-orbit torque efficiency is evaluated using optimized quantum transport methodology and found to be comparable to heavy nonmagnetic metals. The coexistence of magnetism and spin-orbit coupling …

在二维磁体中切换反铁磁和铁磁Skyrmion

Switching between Antiferromagnetic and Ferromagnetic Skyrmions in Two-Dimensional Magnets

通过应变调控磁相互作用，在二维Janus单层Cr2Ge2Te3S3中实现反铁磁与铁磁Skyrmion相的切换，揭示了应变诱导相变机制。