Signature of antiferromagnetic long-range order in the optical spectrum of strongly correlated electron systems
Prof. Dr. Giorgio Sangiovanni (Institut für Theoretische Physik und Astrophysik, Universität Würzburg)

Understanding the crossover from weak- to strong-coupling Mott antiferromagnets and the properties of a single hole moving in the antiferromagnetic phase of the Hubbard model is crucial for strongly correlated materials. Here the problem of the optical conductivity in Mott antiferromagnets is addressed. I will show dynamical mean field theory calculations for the Hubbard model in the long-range order antiferromagnetic (AF) phase. These allowed us to determine the characteristic features of the optical conductivity of a Mott antiferromagnet. This study was motivated by the interesting experimental observation of multiple peaks in the optical conductivity of Mn-based compounds, whose origin has not yet been understood, and provides a tool to detect the characteristics of antiferromagnetism arising from strong electronic correlations.