Electrodynamic response of t_2g electron systems

A promising approach for advancing materials in quantum physics is to harness the correlated phases in t_2g systems of transition metal compounds, such as iridates and ruthenates. Light-matter interactions offer a powerful means to probe these phases, providing valuable insights into low-energy excitations and phase transitions. To explore this, we have studied the electrodynamic responses in t_2g systems using group-theoretic quantum chemistry and many-body methods. By applying the Matsubara formalism and modeling electron correlations through a Hartree-Fock mean-field approach, we have analyzed the interplay between competing spin-orbit coupling and Jahn-Teller interactions in the phase diagram of correlated t_2g electron states. Furthermore, we have mapped the interactions between electromagnetic waves and electrons across varying frequencies, spin-orbit coupling strengths, electronic correlations, and Jahn-Teller effects. Our results underscore the competition between spin-orbit coupling and Jahn-Teller interactions in t_2g systems and reveal the role of temperature and electron correlations in shaping this competition.