Figure 1

Left: False color scanning electron micrograph of the measured GNR sample; green color marks graphene and blue denotes the silicon oxide substrate. Terminals 1 and 3 were employed for cross correlation while bias was supplied via 2 and 4 in the HBT experiments. The white scale bar corresponds to 100 nm. The overlaid arrows define the straight and bent carrier paths with conductances of \({G}_{p}\) and \({G}_{t}\) in the central region, respectively, for electrons coming from terminal 1; the same definition of \({G}_{p}\) and \({G}_{t}\) repeats for electrons coming from each terminal. Right: Schematic illustration of our theoretical model with its most essential features: \({G}_{0}\) denotes the average arm conductance, \(\widehat{G}\) describes the transport in the semiballistic central region, \({f}_{i}^{c}\) and \({\phi }_{i}^{c}\) mark the non-equilibrium distribution and the local voltage at the contact point between the diffusive arm and the central region, and \({f}_{0}(E)\) denotes the Fermi distribution. In the diffusive arm, the distribution function varies as \({f}_{i}(x,\,E)=(1-\frac{x}{L}){f}_{0}(E-e{V}_{i})+\frac{x}{L}\,{f}_{i}^{c}(E)\). For details, see text.