Electronic correlations and Fermi liquid behavior of intermediate-band states in titanium-doped silicon

TL;DR

This paper investigates the electronic states in titanium-doped silicon, revealing a metallic intermediate band with Fermi-liquid behavior and coherent quasi-particles, combining electronic correlations and disorder effects.

Contribution

It introduces a combined theoretical approach using dynamical mean-field theory and disorder models to study intermediate-band states in doped silicon.

Findings

Extended metallic state with depleted density of states at Fermi level

Self-energy characteristic of Fermi liquids

Existence of coherent quasi-particles at certain temperatures

Abstract

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 to Fermi-liquids and for certain temperatures reveals the existence of coherent quasi-particles.