Force-detected electron-spin resonance: Adiabatic inversion, nutation, and spin echo

Electron-spin resonance of $E^{\prime }$ centers in vitreous silica was studied using force-detection techniques at temperatures down to 5 K. Cyclic adiabatic inversion of electron spins was performed by frequency modulation of the applied microwave magnetic field. This produced an oscillatory magnetic force between the electron spins and a nearby permanent magnet, resulting in the vibration of a cantilever on which the sample was mounted. By pulsing the microwave field prior to the force-detection sequence, nutation of the spins could be observed. Spin echoes were observed mechanically using a modified echo-pulse sequence. The decay of magnetization during cyclic adiabatic inversion was also studied and is discussed in terms of utility for future single-spin detection experiments.