Near the 100th anniversary of the discovery of ferroelectricity, so-called sliding ferroelectricity has been proposed and confirmed recently in a series of experiments that have stimulated remarkable interest. Such ferroelectricity exists widely and exists only in two-dimensional (2D) van der Waals stacked layers, where the vertical electric polarization is switched by in-plane interlayer sliding. Reciprocally, interlayer sliding and the “ripplocation” domain wall can be driven by an external vertical electric field. The unique combination of intralayer stiffness and interlayer slipperiness of 2D van der Waals layers greatly facilitates such switching while still maintaining environmental and mechanical robustness at ambient conditions. In this perspective, we discuss the progress and future opportunities in this behavior. The origin of such ferroelectricity as well as a general rule for judging its existence are summarized, where the vertical stacking sequence is crucial for its formation. This discovery broadens 2D ferroelectrics from very few material candidates to most of the known 2D materials. Their low switching barriers enable high-speed data writing with low energy cost. Related physics like Moiré ferroelectricity, the ferroelectric nonlinear anomalous Hall effect, and multiferroic coupling are discussed. For 2D valleytronics, nontrivial band topology and superconductivity, their possible couplings with sliding ferroelectricity via certain stacking or Moiré ferroelectricity also deserve interest. We provide critical reviews on the current challenges in this emerging area.

在铁电体发现 100 周年之际，人们提出了所谓的滑动铁电体，并在最近的一系列实验中得到了证实，这些实验引起了极大的兴趣。这种铁电性广泛存在并且仅存在于二维（2D）范德华堆叠层中，其中垂直电极化通过面内层间滑动来切换。反过来，层间滑动和“涟漪”畴壁可以由外部垂直电场驱动。2D 范德华层的层内刚度和层间滑动性的独特组合极大地促进了这种转换，同时在环境条件下仍保持环境和机械稳健性。从这个角度来看，我们讨论了这种行为的进展和未来的机会。总结了这种铁电性的起源以及判断其存在的一般规则，其中垂直堆叠顺序对其形成至关重要。这一发现将二维铁电体从极少的候选材料扩展到大多数已知的二维材料。它们的低开关势垒能够以低能耗实现高速数据写入。讨论了莫尔铁电性、铁电非线性反常霍尔效应和多铁耦合等相关物理。对于二维谷电子学、非平凡能带拓扑和超导，它们可能通过某些堆叠或莫尔铁电与滑动铁电耦合也值得关注。我们对这一新兴领域的当前挑战进行了批判性评论。其中垂直堆叠顺序对其形成至关重要。这一发现将二维铁电体从极少的候选材料扩展到大多数已知的二维材料。它们的低开关势垒能够以低能耗实现高速数据写入。讨论了莫尔铁电性、铁电非线性反常霍尔效应和多铁耦合等相关物理。对于二维谷电子学、非平凡能带拓扑和超导，它们可能通过某些堆叠或莫尔铁电与滑动铁电耦合也值得关注。我们对这一新兴领域的当前挑战进行了批判性评论。其中垂直堆叠顺序对其形成至关重要。这一发现将二维铁电体从极少的候选材料扩展到大多数已知的二维材料。它们的低开关势垒能够以低能耗实现高速数据写入。讨论了莫尔铁电性、铁电非线性反常霍尔效应和多铁耦合等相关物理。对于二维谷电子学、非平凡能带拓扑和超导，它们可能通过某些堆叠或莫尔铁电与滑动铁电耦合也值得关注。我们对这一新兴领域的当前挑战进行了批判性评论。它们的低开关势垒能够以低能耗实现高速数据写入。讨论了莫尔铁电性、铁电非线性反常霍尔效应和多铁耦合等相关物理。对于二维谷电子学、非平凡能带拓扑和超导，它们可能通过某些堆叠或莫尔铁电与滑动铁电耦合也值得关注。我们对这一新兴领域的当前挑战进行了批判性评论。它们的低开关势垒能够以低能耗实现高速数据写入。讨论了莫尔铁电性、铁电非线性反常霍尔效应和多铁耦合等相关物理。对于二维谷电子学、非平凡能带拓扑和超导，它们可能通过某些堆叠或莫尔铁电与滑动铁电耦合也值得关注。我们对这一新兴领域的当前挑战进行了批判性评论。他们可能通过某些堆叠或莫尔铁电与滑动铁电耦合也值得关注。我们对这一新兴领域的当前挑战进行了批判性评论。他们可能通过某些堆叠或莫尔铁电与滑动铁电耦合也值得关注。我们对这一新兴领域的当前挑战进行了批判性评论。