  The tunnel current (TC) and valley current (VC) are crucial in realizing
high-speed and energy-saving in next-generation devices. This paper presents
the TC and VC link in the partially overlapped graphene. Under the vertical
electric field, the two graphene layers have the opposite AB sublattice
symmetry, followed by a block on the intravalley transmission. In the allowed
intervalley transmission, the difference in the phase of the decay factor
prefers only one of the valleys in the output according to the overlapped
length. These results suggest that the band gap with no edge state is a new
platform of valleytronics.
