Abstract Interfaces are the birthplace of a multitude of fascinating discoveries in fundamental science, and have enabled modern electronic devices, from transistors, to lasers, capacitors or solar cells. These interfaces between bulk materials are always bi-dimensional (2D) ‘surfaces’. However the advent of graphene and other 2D crystals opened up a world of possibilities, as in this case the interfaces become one-dimensional (1D) lines. Although the properties of 1D nanoribbons have been extensively discussed in the last few years, 1D interfaces within infinite 2D systems had remained mostly unexplored until very recently. These include grain boundaries in polycrystalline samples, or interfaces in hybrid 2D sheets composed by segregated domains of different materials (as for example graphene/BN hybrids, or chemically different transition metal dichalcogenides). As for their 2D counterparts, some of these 1D interfaces exhibit polar characteristics, and can give rise to fascinating new physical properties. Here, recent experimental discoveries and theoretical predictions on the polar discontinuities that arise at these 1D interfaces will be reviewed, and the perspectives of this new research topic, discussed.

中文翻译：

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单层材料中的极性不连续性和一维界面

摘要 接口是基础科学中众多引人入胜的发现的发源地，并且使现代电子设备（从晶体管到激光器、电容器或太阳能电池）成为可能。散装材料之间的这些界面始终是二维 (2D)“表面”。然而，石墨烯和其他 2D 晶体的出现开辟了一个充满可能性的世界，因为在这种情况下，界面变成了一维 (1D) 线。尽管一维纳米带的特性在过去几年中得到了广泛的讨论，但直到最近，无限二维系统中的一维界面仍然大部分未被探索。这些包括多晶样品中的晶界，或由不同材料的分离域组成的混合二维片中的界面（例如石墨烯/BN 混合，或化学上不同的过渡金属二硫属化物）。至于它们的 2D 对应物，这些 1D 界面中的一些具有极性特征，并且可以产生令人着迷的新物理特性。在这里，将回顾最近在这些一维界面上出现的极不连续性的实验发现和理论预测，并讨论这一新研究课题的前景。