Multiferroic materials have attracted considerable attention owing to their unique magnetoelectric or magnetooptical properties. The recent discovery of few-layer van der Waals multiferroic crystals provides a new research direction for controlling the multiferroic properties in the atomic layer limit. However, research on few-layer multiferroic crystals is limited and the effect of thickness-dependent symmetries on those properties is less explored. In this study, the symmetries and magnetoelectric responses of van der Waals multiferroic CuCrP₂S₆ are investigated by optical second harmonic generation (SHG). Structural and magnetic phase transitions are successfully probed by the temperature-dependent SHG signals, revealing significant changes by applying the magnetic field reflecting the magnetoelectric effect. Moreover, it is found that symmetries and resultant magnetoelectric responses can be modulated by the number of layers. These results offer a new principle of controlling the multiferroicity and indicate that 2D van der Waals multiferroic material is a promising building block for functional nanodevices.

中文翻译：

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二维多铁性 CuCrP2S6 磁电对二次谐波产生的巨调制

多铁材料由于其独特的磁电或磁光特性而引起了广泛的关注。最近发现的少层范德华多铁性晶体为原子层极限内控制多铁性提供了新的研究方向。然而，对少层多铁晶体的研究是有限的，并且厚度相关的对称性对这些特性的影响也很少被探索。在本研究中，通过光学二次谐波发生（SHG）研究了范德华多铁性CuCrP ₂ S ₆的对称性和磁电响应。通过温度相关的二次谐波信号成功探测了结构和磁性相变，通过施加反映磁电效应的磁场揭示了显着的变化。此外，还发现对称性和由此产生的磁电响应可以通过层数进行调制。这些结果提供了控制多铁性的新原理，并表明二维范德华多铁性材料是功能纳米器件的有前途的构建模块。