Study of the gap formation in Kondo insulators

Motivated by recent experimental measurements of the temperature-dependent gap formation in the Kondo insulator SmB$_6$ (Matsunami et al.) we investigate the Periodic Anderson Model at half-filling and in the strong-coupling regime. We solve this model in three dimensions using the Dynamical Cluster Approximation to incorporate non-local correlations and the Maximum Entropy Method to derive the spectral functions. We calculate the temperature dependence of the insulating gap and the screened moment, and discuss how the appearance of the gap is related with the lattice Kondo screening.