  We study the quantum valley Hall effect and related domain wall modes in
twisted bilayer graphene at a large commensurate angle. Due to the quantum
valley and sub-valley Hall effect, a small deviation from the commensurate
angle generates two-dimensional conducting network patterns composed of
one-dimensional domain wall conducting channels, which can induce non-Fermi
liquid transport behavior within an accessible temperature range. The domain
wall modes can be manipulated by using the layer shifting and external electric
fields which, in turn, leads to the sub-valley Haldane and Semenoff masses on
the domain wall modes. The large-angle twisted bilayer graphene and related
materials can be a new setup to harness the quantum valley and sub-valley Hall
effect with enhanced tunability.
