Modulation of electronic properties with external fields in silicene-based nanostructures

This work reviews our recent works about the density functional theory (DFT) calculational aspects of electronic properties in silicene-based nanostructures with the modulation of external fields, such as electric field, strain, etc. For the two-dimensional (2D) silicene-based nonostructures, the magnetic moment of Fe-doped silicene shows a sharp jump at a threshold electric field, which indicates a good switching effect, implying potential applications as a magnetoelectric (ME) diode. With the electric field, the good controllability and sharp switching of the magnetism may offer a potential applications in the ME devices. For the one-dimensional (1D) nanostructures, the silicene nanoribbons with sawtooth edges (SSiNRs) are more stable than the zigzag silicene nanoribbons (ZSiNRs) and show spin-semiconducting features. Under external electric field or uniaxial compressive strain, the gapless spin-semiconductors are gained, which is significant in designing qubits for quantum computing in spintronics. The superlattice structures of silicene-based armchair nanoribbons (ASiSLs) is another example for 1D silicene nanostructures. The band structures of ASiSLs can be modulated by the size and strain of the superlattices. With the stain increased, the related energy gaps of ASiSLs will change, which are significantly different with that of the constituent nanoribbons. The results suggest potential applications in designing quantum wells.