Nonreciprocal and nonlinear charge transport effect in dual-gated bilayer graphene

The search for single-phased material systems that show large nonreciprocal and nonlinear charge transport effect (NRTE) has attracted many attentions recently, which may lead to promising electronic applications. Here, we demonstrated such a NRTE in a dual-gated bilayer graphene (BLG) system without requiring external magnetic field. Owing to the unique pseudospin (or valley) degree of freedom in gapped chiral fermions with trigonal warping, the displacement field applied on a BLG not only breaks the inversion symmetry but also effectively removes the cancellation of NRTE from two different valleys, and it results in a large NRTE signal that grows with the excitation current and displacement field strength. The demonstration of full electric-field tuning of the nonreciprocal transport effect without magnetic field may provide an alternative route for valleytronics using two-dimensional based devices.