Shot noise in electrically-gated silicene nanostructures

We have theoretically studied fundamental shot noise properties in single- and dual-gated silicene nanostructures. It is demonstrated here that due to the intrinsic spin-orbit gap, the Fano factor ( F ) in the biased structures does not coincide with the characteristic value F  = 1/3, a value frequently reported for a graphene system. Under gate-field modulations, the F in the gated structure can be efficiently engineered and the specific evolution of the F versus the field strength is symmetric with the center of spectra oppositely shifting away from the zero field condition for the valley or spin-coupled spinor states. This field-dependent hysteretic loop thus offers some flexible methods to distinguish one spinor state from its valley or spin-coupled state via their numerical difference in the F once the incident beam is spin or valley-polarized.