Electronic correlations and Fermi liquid behavior of intermediate-band states in titanium-doped silicon
We study the nature of the electronic states in the intermediate band formed by interstitial titanium in silicon. Our single-site description combines effects of electronic correlations, captured by dynamical mean-field theory, and disorder, modeled using the coherent potential approximation and the typical medium mean-field theory. For all studied concentrations an extended metallic state with a strongly depleted density of states at the Fermi level is obtained. The self-energy is characteristic of Fermi liquids and for certain temperatures reveals the existence of coherent quasiparticles.