▎ 摘　　要

Recently, the AA-stack bilayer graphene nanoribbon (BGN) with a closed edge is observed in experiment. This new type of GN, we called folded GN (FGN), can be formed by folding a monolayer GN (MGN). Electron transport of the folded structures with different edges is studied. The FGNs show unique transport properties different from those of MGNs and BGNs. A metallic MGN with armchair edge (MAGN) is still metallic after folding. However, a semiconducting MAGN can be either semiconducting or metallic after folding, which depends on the width of MAGN and strength of interlayer coupling in the folded structure. The energy gap decreases with the increase of the coupling strength or width. As to the MGNs with zigzag edge (MZGNs), after folding they exhibit interesting conductance characteristics. The conductance steps around the Dirac point are even multiple of G(0)=2e(2)/h, while other conductance steps are odd multiple of G(0). It indicates that the electron transport around the Dirac point in zigzag-edged FGNs (FZGNs) is similar to that in zigzag-edged BGNs (BZGNs), while electron transport far from the Dirac point is similar to that in zigzag-edged MGNs (MZGNs). (C) 2009 American Institute of Physics. [doi:10.1063/1.3261757]