  In gated bilayer graphene, topological zero-line modes (ZLMs) appear along
lines separating regions with opposite valley Hall topologies. Although it is
experimentally difficult to design the electric gates to realize ZLMs due to
the extremely challenging techniques, twisted bilayer graphene provides a
natural platform to produce ZLMs in the presence of uniform electric field. In
this Letter, we develop a set of wavepacket dynamics, which can be utilized to
characterize various gapless edge modes and can quantitatively reproduce the
electronic transport properties at topological intersections. To our surprise,
in the minimally twisted bilayer graphene where a topological trifurcation
intersection naturally arises, we show that the counterintuitive current
partition (i.e., the direct transport propagation) originates from the
microscopic mechanism "bypass jump". Our method can be applied to understand
the microscopic pictures of the electronic transport features of all kinds of
topological states.
