The recent discovery of two-dimensional (2D) ferromagnetism in van der Waals materials has opened the door to the control of 2D magnetism by means of electric field. Here we demonstrate the magnetization reversal through switching polarization in a designed 2D multiferroic oxide by combining group theory analysis and first-principles calculation. We show that ferroelectricity can be induced by a specific octahedral rotation in a perovskite bilayer. Ferromagnetism can be introduced simultaneously by extending the guideline to the B-site ordered double-perovskite bilayer. We have found two coupling mechanisms between polarization and magnetization that enable the reversal of the in-plane magnetization by ferroelectric switching. Our work provides guidelines for the design of 2D multiferroics with intrinsic magnetoelectric coupling and helps to control the 2D magnetism by electric field.

中文翻译：

---

直接极化-磁化耦合的二维多铁体设计。

范德华材料中二维（2D）铁磁性的最新发现为通过电场控制2D磁性打开了大门。在这里，我们通过结合群论分析和第一性原理计算，证明了在设计的二维多铁氧化物中通过转换极化的磁化反转。我们显示铁电可以通过钙钛矿双层中的特定八面体旋转来诱导。通过将指南扩展到B站点有序双层钙钛矿双层，可以同时引入铁磁性。我们已经发现了极化和磁化之间的两种耦合机制，它们可以通过铁电开关来反转面内磁化。