论文标题
基于石墨烯的异层中的跨层滑动铁电力：下一个邻居互层耦合的不对称性
Across-Layer Sliding Ferroelectricity in Graphene-Based Heterolayers: Asymmetry of Next Neighbor Interlayer Couplings
论文作者
论文摘要
尽管大多数二维（2D）材料是非有线晶格的，但在某些堆叠顺序下可能会在双层中发生对称性破裂，从而导致所谓的滑动铁电力，在这种情况下，垂直极性可以通过Interlayer翻译通过垂直偏转。然而，它不应该出现在任何堆叠构型中具有质心对称性的石墨烯双层等系统中，并且在H-BN（自然2020，588，71）之间插入的石墨烯双层中最近报道的铁电性的起源仍然不清楚。在这里，我们提出了一个跨层滑动铁电的模型，该模型是由下一个邻居互层耦合的不对称性产生的。可以通过多层滑动切换插入式质心对称2D材料（例如石墨烯双层）中的垂直极化，并且可以阐明观察到的铁电滞后。此外，这种铁电性可以存在于具有准排定极性状态的其他一系列异层中，例如石墨烯双层或BN底物上的三层，甚至在表面上具有分子层，每个分子都可以独立地存储1个位数据，从而独立解决高密度数据存储的瓶颈发出的瓶颈。
Although most two-dimensional (2D) materials are non-ferroelectric with highly symmetric lattices, symmetry breaking may take place in their bilayers upon certain stacking order, giving rise to so-called sliding ferroelectricity where the vertical polarizations can be electrically reversed via interlayer translation. However, it is not supposed to appear in systems like graphene bilayer with centro-symmetry at any stacking configuration, and the origin of the recently reported ferroelectricity in graphene bilayer intercalated between h-BN (Nature 2020, 588, 71) is still unclear. Here we propose a model of across-layer sliding ferroelectricity that arises from the asymmetry of next neighbor interlayer couplings. The vertical polarizations in intercalated centro-symmetric 2D materials like graphene bilayer can be switched via multilayer sliding, and the observed ferroelectric hysteresis can be clarified. Moreover, such ferroelectricity can exist in a series of other heterolayers with quasi-degenerate polar states, like graphene bilayer or trilayer on BN substrate, or even with a molecule layer on surface where each molecule can store 1 bit data independently, resolving the bottleneck issue of sliding ferroelectricity for high-density data storage.
