论文标题
应变驱动的零视野接近10 nm的二维范德华异质结构
Strain-Driven Zero-Field Near-10 nm Skyrmions in Two-Dimensional van der Waals Heterostructures
论文作者
论文摘要
磁性Skyrmions $ - $本地化的手性旋转结构$ - $在Spintronic应用中显示出巨大的希望。最近发现的二维（2D）磁性材料为探索原子薄的范德华（VDW）材料中的这种拓扑自旋结构提供了新的机会。尽管最近在2D磁铁中稳定亚稳态的天空量的进展，但尚未探索它们的直径超过100〜nm，并且尚未探索它们的寿命，这对于应用来说是必不可少的。在这里，使用第一原理计算和原子旋转模拟，我们预测压缩机械应变会导致稳定零场天空，直径接近10 nm，在fe $ _3 $ _3 $ gete $ _2 $/dermanene VDW异质结构中。这些独特的天空的起源归因于Dzyaloshinskii-Moriya相互作用的高可调节性和含量的磁晶和磁性各向异性能量，这种效果被证明是Fe $ _3 $ gete $ _2 $ _2 $ _2 $ heterystrouctures与扣子的效果。基于我们针对磁相互作用的第一原理参数，我们使用过渡状态理论计算了保护天空免受歼灭及其寿命的能量屏障。我们表明，在紧张的Fe $ _3 $ Gete $ _2 $/Germanene中，纳米级的天空敏度在高达20 k的温度下可以稳定。
Magnetic skyrmions $-$ localized chiral spin structures $-$ show great promise for spintronic applications. The recent discovery of two-dimensional (2D) magnetic materials opened new opportunities for exploring such topological spin structures in atomically thin van der Waals (vdW) materials. Despite recent progress in stabilizing metastable skyrmions in 2D magnets, their diameters are still beyond 100~nm and their lifetime, which is essential for applications, has not been explored yet. Here, using first-principles calculations and atomistic spin simulations, we predict that compressive mechanical strain leads to stabilizing zero-field skyrmions with diameters close to 10 nm in a Fe$_3$GeTe$_2$/germanene vdW heterostructure. The origin of these unique skyrmions is attributed to the high tunability of Dzyaloshinskii-Moriya interaction and magnetocrystalline anisotropy energy by strain, an effect which is shown to be general for Fe$_3$GeTe$_2$ heterostructures with buckled substrates. Based on our first-principles parameters for the magnetic interactions, we calculate the energy barriers protecting skyrmions against annihilation and their lifetimes using transition-state theory. We show that nanoscale skyrmions in strained Fe$_3$GeTe$_2$/germanene can be stable for hours at temperatures up to 20 K.
