  In graphene nanoribbon junctions, the nearly perfect transmission occurs in
some junctions while the zero conductance dips due to anti-resonance appear in
others. We have classified the appearance of zero conductance dips for all
combinations of ribbon and junction edge structures. These transport properties
do not attribute to the whole junction structure but the partial corner edge
structure, which indicates that one can control the electric current simply by
cutting a part of nanoribbon edge. The ribbon width is expected to be narrower
than 10 nm in order to observe the zero conductance dips at room temperature.
