The zigzag edges of single- or few-layer graphene are perfect one-dimensional conductors owing to a set of gapless states that are topologically protected against backscattering. Direct experimental evidence of these states has been limited so far to their local thermodynamic and magnetic properties, determined by the competing effects of edge topology and electron–electron interaction. However, experimental signatures of edge-bound electrical conduction have remained elusive, primarily due to the lack of graphitic nanostructures with low structural and/or chemical edge disorder. Here, we report the experimental detection of edge-mode electrical transport in suspended atomic-scale constrictions of single and multilayer graphene created during nanomechanical exfoliation of highly oriented pyrolytic graphite. The edge-mode transport leads to the observed quantization of conductance close to multiples of G₀ = 2e²/h. At the same time, conductance plateaux at G₀/2 and a split zero-bias anomaly in non-equilibrium transport suggest conduction via spin-polarized states in the presence of an electron–electron interaction.

中文翻译：

---

石墨烯原子尺度点接触中的量化边缘模式

单层或几层石墨烯的锯齿形边缘是理想的一维导体，这是由于存在一组无间隙状态，这些状态在拓扑上受到了防止反向散射的保护。到目前为止，这些状态的直接实验证据仅限于其局部热力学和磁性能，这取决于边缘拓扑和电子-电子相互作用的竞争效应。然而，主要由于缺乏具有低结构和/或化学边缘紊乱的石墨纳米结构，边缘结合的电传导的实验特征仍然难以捉摸。在这里，我们报告了在高取向热解石墨的纳米机械剥离过程中产生的单层和多层石墨烯的悬浮原子级缩颈中边缘模式电传输的实验检测。G ₀  ＝2e ² / h。与此同时，电导plateaux在ģ ₀ /2和在非平衡传输分割零偏置异常建议通过自旋极化态传导中的电子-电子相互作用的存在。