Robust pure spin current induced by the photogalvanic effect in half-silicane with spatial inversion symmetry.

The spin-dependent photogalvanic (PG) effect in low-dimensional spin semiconductors has attracted great interest recently. Here, we have studied the spin semiconducting feature and spin-dependent photocurrent in a two-dimensional (2D) silicene-based device with spatial inversion symmetrical half-hydrogenation, in which half of the silicene is hydrogenated on the upper surface and half is hydrogenated on the lower surface. Because of the unique spin semiconductor properties and symmetry of the system, pure spin current can be robustly produced in both the zigzag and armchair directions for linearly and elliptically polarized light.

Newly discovered graphyne allotrope with rare and robust Dirac node loop.

Two-dimensional (2D) carbon allotropes with topologically nontrivial states are drawing considerable attention owing to their unique physical properties and great potential applications in the next generation of micro-nano devices. In contrast to the numerous Dirac points predicted in 2D carbon allotropes, systems featuring Dirac nodal lines (loops) are still quite rare. Here, by means of first-principles calculation, we report our newly discovered carbon monolayer 123-E8Y24-1 with robust Dirac nodal line states, which possesses a tetragonal lattice with P4/mmm symmetry and contains 8 sp carbon atoms (graphene: E8) and 24 sp carbon atoms (grapheyne: Y24) in the crystalline cell.

Effect of hydrogen passivation on the decoupling of graphene on SiC(0001) substrate: First-principles calculations.

Intercalation of hydrogen is important for understanding the decoupling of graphene from SiC(0001) substrate. Employing first-principles calculations, we have systematically studied the decoupling of graphene from SiC surface by H atoms intercalation from graphene boundary. It is found the passivation of H atoms on both graphene edge and SiC substrate is the key factor of the decoupling process.