Spectroscopic study of nuclear magnetic resonance induced by oscillating electron spin domain walls

Nuclear electric resonance (NER), where nuclear spin resonance is mediated by oscillating electron-spin domain walls, is studied by applying radio-frequency electric fields to a GaAs-based two-dimensional electron system. In contrast with conventional resistively detected nuclear magnetic resonance, the NER signal appears not only at the resonance frequency, fLfL, but also at fL/2,fL/3fL/2,fL/3, and so on. The amplitudes of NER signal are semi-quantitatively explained using a simple model based on the spatial oscillation of a domain wall and the resultant spatial distribution of the spectral density of the fundamental and harmonic components.