Fabrication and characterization of nanometer-sized gaps in suspended few-layer graphene devices

Graphene nanodevices, such as ultra-narrow constrictions and nanometer-spaced gaps, are emerging as appealing candidates for various applications, ranging from advanced quantum devices to single-molecule junctions and even DNA sequencing. Here, we present the realization and characterization of nanometer-sized gaps in suspended few-layer graphene devices via feedback-controlled electroburning at room temperature. By analyzing the electrical behavior after the electroburning process, we identify two distinct regimes for the resulting devices, deriving a simple yet effective quantitative criterion to determine the complete opening of the nanogaps.