Electron spin states embedded in localized states for opening spin levels effect in silicon nanowires doped with impurities

Abstract

We measure a dramatic increase of spin states splitting in the localized states in silicon [001] nanowire doped with impurities. To verify the opening spin levels effect, we conduct fine IV measurements under laser irradiation, and observe their change under magnetic field in the novel photo-electron conductivity detection. A strong spin oscillation occurs in the fine IV measurement of oxygen doped nanowires only under a laser illumination at wavelength of 633 nm. In room temperature photo-luminescence, the spin splitting of the emission peaks is dramatically opened to spin gap of 140 meV. These behaviors are attributed to the spin states embedded in the localized states. This hypothesis can be supported by an atomic model of coupling between the spin states and the localized states in the first principle simulation platform. We believe the incorporation of oxygen in silicon nanowire leads symmetry broken which is heavily dependent on the silicon nanostructure. Our simulation reveals that splitting of the electronic spin levels as large as 320 meV can be obtained in the localized states of SiO double bond. The formula is found to describe the relationship between the opening gap of spin levels splitting and the symmetry broken degree.