Electrical-Controlled Transport for Surface States in a Dirac Semimetal Quantum Wire

The transport properties of a Dirac semimetal quantum wire with two side gates are theoretically studied by adopting the lattice Green function method. It is found that a residual conductance quantum contributed from the surface states can be switched on or off by tuning the electron energy or the side gates voltage. This ideal switching effect for the surface Dirac electron results from the transversal quantum confinement of the quantum wire in combination with the electrostatic potential induced by the side gates. These findings may provide useful guidance for designing all-electrical topological nanoelectronic devices.