Slave-particle studies of Mott systems

Y. Komijani, K.~Hallberg, G. Kotliar, , Renormalized dispersing multiplets in the spectrum of nearly Mott localized systems, Phys. Rev. B 99, 125150 (2019).

Y. Komijani, G. Kotliar, , Analytical slave-spin mean-field approach to orbital selective Mott insulators, Phys. Rev. B 96, 125111 (2017).

• In spite of extensive research, strongly correlated systems in dimensions larger than one, are in general difficult to tame theoretically. Dynamical mean-field theory (DMFT) is the only reliable tool in our disposal which maps the problem to an impurity embedded in an effective bath with systematic corrections.
• Slave-particle mean-field methods are alternative approaches that are numerically much lighter and by capturing both atomic limit and the non-interacting bandstructure offer a quick glimpse on the effects of interaction in the system.
• In this work, we showed that slave-particle mean-field method can be used to study subgap multiplets that appear in the spectrum of strongly correlated systems.
• This is specially interesting in the so-called orbitally selective Mott (OSM) phase, where one orbital undergoes a Mott localziation, whereas the other orbital remains itinerant.
• We compared the mean-field results with those of DMFT and find a good agreement. The resonces in red (solid for mean-field, dotted for DMFT) arise due to a boundstate of a holon in one orbital and doublon in the other.
• A related question is whether or not the OSM phase stable against various interactions and/or inter-orbital tunnelling.