Distribution of frequencies of a single precessing spin detected by scanning tunneling microscope

We have measured high frequency signals in the tunneling current of scanning tunneling microscopy for a submonolayer oxide thin film on the Si(111)-7 x 7 surface. We demonstrate that the signal is related to the Larmor precession of the electron spin associated with a dangling bond. The detected precession frequency possesses a broad distribution (linewidth is comparable to that observed by conventional electron spin resonance) and a split near the maxima, both of which are attributed to the inhomogeneity of the g factor of a single spin. (c) 2008 American Institute of Physics.