▎ 摘　　要

This work reports on a method to open nanoscale gaps in h-shaped graphene nano-constrictions by electrical breakdown at room temperature and pressure below 10(-5) mbar. The method was validated on 275 devices, fabricated on eight different chips, using Chemical Vapor Deposition (CVD)-grown graphene from in-house production and from two commercial sources. The gap width was estimated by fitting the I-V traces after electrical breakdown with the Simmons model for the intermediate-voltage range. The statistics on the collected data demonstrates that the method results in normally distributed nanoscale gaps in h-shaped graphene nano-constrictions, with an estimated average width centered around 1 nm and a gap fabrication yield of 95%. (c) 2022 Author(s).All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1063/5.0087564