Josephson-coupled superconducting regions embedded at the interfaces of highly oriented pyrolytic graphite

Abstract

Transport properties of a few hundreds of nanometers thick (in the graphene plane direction) lamellae of highly oriented pyrolytic graphite (HOPG) have been investigated. Current–voltage characteristics as well as the temperature dependence of the voltage at different fixed input currents provide evidence for Josephson-coupled superconducting regions embedded in the internal two-dimensional interfaces of HOPG, reaching zero resistance at low enough temperatures.