Topologically protected ac transport in zigzag silicene nanosystem

The linear ac transport properties are investigated theoretically in zigzag silicene nanoribbon and nanojunction systems. Based on the tight-binding approach and ac response theory, we compute the dc conductance and ac emittance. The topologically protected edge states and eliminated ac emittance are presented around the Dirac point. Emittances as functions of the strength of spin-orbital interaction (SOI) and geometric size of the silicene systems are studied. The results show that the eliminated ac response behavior is induced by the strong SOI and is topologically protected against the size variation.