1] Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA [2].
The University of Tennessee, Knoxville, Tennessee 37996, USA.
Nat Commun. 2014 Nov 7;5:5403. doi: 10.1038/ncomms6403.
Two-dimensional interfaces between crystalline materials have been shown to generate unusual interfacial electronic states in complex oxides. Recently, a one-dimensional interface has been realized in hexagonal boron nitride and graphene planar heterostructures, where a polar-on-nonpolar one-dimensional boundary is expected to possess peculiar electronic states associated with edge states of graphene and the polarity of boron nitride. Here we present a combined scanning tunnelling microscopy and first-principles theory study of the graphene-boron nitride boundary to provide a first glimpse into the spatial and energetic distributions of the one-dimensional boundary states down to atomic resolution. The revealed boundary states are about 0.6 eV below or above the Fermi level depending on the termination of the boron nitride at the boundary, and are extended along but localized at the boundary. These results suggest that unconventional physical effects similar to those observed at two-dimensional interfaces can also exist in lower dimensions.
已经证明，在复杂氧化物中，晶体材料之间的二维界面会产生异常的界面电子态。最近，在六方氮化硼和石墨烯平面异质结构中实现了一维界面，在那里，预期具有极性-非极性一维边界的特殊电子态与石墨烯的边缘态和氮化硼的极性有关。在这里，我们通过扫描隧道显微镜和第一性原理理论研究了石墨烯-氮化硼边界，以首次深入了解一维边界态的空间和能量分布，达到原子分辨率。所揭示的边界态比费米能级低或高约 0.6 eV，取决于边界处氮化硼的终止，并且沿边界延伸但局限于边界。这些结果表明，类似于在二维界面观察到的非常规物理效应也可能存在于更低的维度。
