Spin-orbit entanglement in Mn3+ ions

Spin-orbit entanglement in 3d systems has attracted the attention to realize quantum phases, which may offer advantages with respect to 4d and 5d systems. Interestingly, we have identified recently an alternative path to entanglement in Mn3+ ions (d4) between t_2g^(3,↑↑↑) e_g^(1,↑) (total spin S = 2) and t_2g^(4,↑↑↑↓) e_g^0 (S = 1). This mixing, which we detect by magneto-optical spectroscopy, is driven by the reduction of the energy gap S between the above two configurations, which is strong in the presence of Jahn-Teller distortions. We aim at using pre-edge features in O K-edge XAS spectra to map changes in the energy gap as a function of temperature and microstructural domain configurations in the thin films. XAS measurements will be instrumental to validate the spin-orbit mixing scenario inferred from our magneto-optical spectra. In particular, such spin-orbit entanglement may open new routes for light-induced manipulation of quantum states in other materials where Jahn-Teller physics may be relevant (e.g., cobaltites, cuprates). Additionally, the validation of the model will allow gaining fundamental insights into the nature of electron-lattice coupling and provide important fundamental insights into the nature of spin-orbital-lattice coupling in electronic correlated systems.