Graphene nanogaps are considered as essential building blocks of two-dimensional electronic circuits, as they offer the possibility to interconnect a broad range of atomic-scale objects. Here we provide an insight into the microscopic processes taking place during the formation of graphene nanogaps through the detailed analysis of their low-frequency noise properties. Following the evolution of the noise level, we identify the fundamentally different regimes throughout the nanogap formation. By modeling the resistance and bias dependence of the noise, we resolve the major noise-generating processes: atomic-scale junction-width fluctuations in the nanojunction regime and sub-atomic gap-size fluctuations in the nanogap regime. As a milestone toward graphene-based atomic electronics, our results facilitate the automation of an optimized electrical breakdown protocol for high-yield graphene nanogap fabrication.

石墨烯纳米间隙被认为是二维电子电路必不可少的组成部分，因为它们提供了互连各种原子级物体的可能性。在这里，我们通过对石墨烯纳米间隙的低频噪声特性的详细分析，深入了解了石墨烯纳米间隙形成过程中发生的微观过程。随着噪声水平的发展，我们确定了整个纳米间隙形成过程中根本不同的机制。通过对噪声的电阻和偏置依赖性进行建模，我们解决了主要的噪声生成过程：纳米结区域的原子尺度结宽波动和纳米间隙区域的亚原子间隙尺寸波动。作为基于石墨烯的原子电子学的里程碑，