Electron transport through symmetrical junctions of semimetal graphene ribbons

Based on the nearest-neighbor tight-binding model, we present analytical description of low-energy electron transport through a symmetrical junction of two semimetal armchair ribbons. The results obtained demonstrate the transmission suppression in the vicinity of the neutrality point except for the junction of the ribbons consisting of 3p-1 and 3p+5 dimer lines, p/2 is odd. Unlike other interconnections, these compounds are shown to be free of even local levels arising at the junction interface and exhibit electron backscattering to be inversely as the square of p+1.