Effect of Kondo resonance on optical third harmonic generation
  We use the method of dynamical mean field thoery, to study the effect of Kondo resonance on optical third harmonic generation (THG) spectra of strongly correlated systems across the metal-insulator transition. We find that THG signals are proportional to the quasiparticle weight $z$ of the Kondo peak, and are precursors of Mott-Hubbard gap formation. 
S.A. Jafari, T. Tohyama, S. Maekawa