Conductance of armchair silicene nanoribbon junctions

Using the non-equilibrium Green's function method, the conductance (G) of armchair silicene nanoribbon (ASiNR) junctions are studied. The width of the left (right) ASiNR is denoted as N-L (N-R), and N-L > N-R. With decreasing N-L-N-R, G increases as a whole. With increasing N-L or N-R , the number (width) of conductance plateaus in the low energy region increases (decreases). When N-L-N-R = 14 or 26, a conductance peak appears at E-F = 0. For metal/semiconductor (M/S), semiconductor/metal (S/M), and semiconductor/semiconductor (S/S) ASiNR junctions with N-L-N-R = 10, dips appear in the conductance steps. For metal/metal (M/M) ASiNR junctions, two dips (G = 0) and one peak around E-F = 0 turn up when N-L-N-R increases to a certain extent. For S/M (S/S) ASiNR junctions, the width of the conductance gap (Delta E-G) is determined by the energy gap of the left (right) semiconducting ASiNR. For M/S ASiNR junctions, Delta E-G is determined jointly by the energy gap of the left metallic and right semi-conducting ASiNRs.