Using spin-polarized scanning tunneling microscopy and density functional theory, we have studied the magnetic properties of $\mathrm{Pd}/\mathrm{Fe}$ atomic bilayers on Re(0001). Two kinds of magnetic ground states are discovered due to different types of stacking of the Pd adlayer on $\mathrm{Fe}/\mathrm{Re}(0001)$. For fcc stacking of Pd on $\mathrm{Fe}/\mathrm{Re}(0001)$, it is a spin spiral propagating along the close-packed ($\overline{\mathrm{\Gamma }K}$) direction with a period of about 0.9 nm, driven by frustrated exchange and Dzyaloshinskii-Moriya interactions. For the hcp stacking, the four-site four-spin interaction stabilizes an up-up-down-down state propagating perpendicular to the close-packed direction (along $\overline{\mathrm{\Gamma }M}$) with a period of about 1.0 nm. Our work shows how higher-order exchange interactions can be tuned at interfaces.

中文翻译：

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Re（0001）上Pd / Fe双层中的堆积相关自旋相互作用

使用自旋极化扫描隧道显微镜和密度泛函理论，我们研究了铁的磁性 $钯/铁$Re（0001）上的原子双层。由于Pd沉积层在Pd上的堆积类型不同，发现了两种磁性基态$铁/\mathrm{回覆}（0001）$。对于FCC堆叠的钯$铁/\mathrm{回覆}（0001）$，它是沿着密排（$\overline{\mathrm{\Gamma }ķ}$方向约为0.9 nm，受挫的交换和Dzyaloshinskii-Moriya相互作用驱动。对于hcp堆叠，四位四旋相互作用稳定了垂直于密排方向传播的上-下-下状态$\overline{\mathrm{\Gamma }\mathrm{中号}}$）的周期约为1.0 nm。我们的工作显示了如何在接口上调整高阶交换交互。