Interlayer Sliding Induced Triferroic Coupling in 2D Bilayer NbSi2N4

作者：Yue Yang, Ying Zhao, Fanhan Kong, Qinxi Liu, Yan Su, Jijun Zhao, Xue Jiang · 发表于：The Journal of Physical Chemistry Letters · 年份：2025 · DOI：10.1021/acs.jpclett.5c02112 · 被引用次数：3 · 研究领域：2D Materials and Applications、Multiferroics and related materials、Perovskite Materials and Applications

Interlayer sliding symmetry breaking presents a powerful technique for achieving intrinsic multiferroic coupling among magnetism, ferroelectricity, and valley polarization, thereby establishing a new paradigm for the design of multifunctional devices. First-principles calculations unveil multiferroic coupling in 2D NbSi 2 N 4 . The monolayer exhibits a ferromagnetic ground state, where valley polarization is tuned by magnetic moment reversal. The energetically stable AB/BA-stacked bilayer hosts coexisting triferroic orders: antiferromagnetism, ferrovalley, and out-of-plane ferroelectricity. The interlayer-sliding-induced AB to BA transition enables non-volatile ferroelectric bistability via polarization reversal. The magneto-optic Kerr effect (MOKE) confirms magnetoelectric coupling between sliding ferroelectricity and antiferromagnetism. Valley polarization reversal is achieved by electric-field-driven polarization switching or magnetic-field-controlled magnetization direction flipping, inducing a significant stacking-dependent anomalous valley Hall effect (AVHE) and spin currents. This establishes NbSi 2 N 4 as an ideal platform for novel non-volatile memory and spin–valleytronic devices.