Fluctuations of g factors in metal nanoparticles: effects of electron-electron interaction and spin-orbit scattering.

We investigate the combined effect of spin-orbit scattering and electron-electron interactions on the probability distribution of g factors of metal nanoparticles. Using random matrix theory, we find that even a relatively small interaction strength significantly increases g-factor fluctuations for not-too-strong spin-orbit scattering (ratio of spin-orbit rate and single-electron level spacing 1/tau(so)delta < or near 1), and leads to the possibility to observe g factors larger than 2.