Magnetic resonance force detection and spectroscopy of electron spins in phosphorus-doped silicon

Electron spin resonance (ESR) of phosphorus-doped silicon was detected using a low temperature magnetic resonance force microscope (MRFM). Force-detected ESR spectra were obtained using an amplitude or frequency modulated microwave field to cyclically saturate the spin magnetization. For a sample containing 4×1018 phosphorus atoms/cm3, a single strong ESR line was observed. For a sample containing 8×1016 phosphorus atoms/cm3, a pair of lines split by the 42 G 31P hyperfine interaction was observed. This result demonstrates the possibility of using MRFM techniques for spectroscopic purposes. © 1997 American Institute of Physics.