A geometric approach to confining a Dirac neutral particle in analogous way to a quantum dot

Based on the transfer-matrix method, the spin transport properties through a graphene-based multi-barrier nanostructure with an exchange field and Rashba spin orbit coupling (SOC), have been investigated. It is found that if Rashba SOC equals to the exchange field, the multi-barrier nanostructure is an efficient way to achieve spin rotators and spin filters. In addition, it is also found that the shot noise of a spin state can be enhanced by electrostatic potential, and plateaus of the Fano factor is formed.