Charge order and non-local correlations in the doped two-dimensional extended Hubbard model.

Various strongly correlated systems reveal exotic phases of matter away from half-filling. To explore how doping, non-local inter-site interactions, and strong correlations affect the charge order phase in two dimensions, we perform a thorough study of the extended Hubbard model at finite temperature and doping at local interactions strength below the Mott limit. We perform our analysis using the cluster dynamical mean-field theory on a cluster of size 8. Our results show that doping leads to the melting of the charge order phase at relatively small doping (15-20%). Also, we find that the interplay of the local and non-local interactions leads to a variety of phase transitions in this model. In particular, we find that under doping, a half-filled charge order insulator with vanishing compressibility first melts into a charge ordered metal. We explore the energetics and the non-local correlations change in and outside of the charge order phase as function of doping.