Adatom defect induced spin polarization of asymmetric structures

The spin polarization of carbon nanomaterials is crucial to design spintronic devices. In this paper, the first-principles is used to study the electronic properties of two defect asymmetric structures, Cap-(9, 0)-Def [6, 6] and Cap-(9, 0)-Def [5, 6]. We found that the ground state of Cap-(9, 0)-Def [6, 6] is sextet and the ground state of Cap-(9, 0)-Def [5, 6] is quartet, and the former has a lower energy. In addition, compared with Cap-(9, 0) CNTs, the C adatoms on C30 causes spin polarization phenomenon and Cap- (9, 0)-Def [6, 6] has more spin electrons than Cap-(9, 0)-Def [5, 6] structure. Moreover, different adsorb defects reveal different electron accumulation. This finding shows that spin polarization of the asymmetric structure can be adjusted by introducing adatom defects.

On the origin of the electron accumulation layer at clean InAs(111) surfaces

We address the electronic properties of bulk InAs and clean InAs(111) surfaces using DFT+U method. On the basis of optimized atomic surfaces we recover STM images and propose a possible explanation for the electron accumulation layer generation.