Correlation strength and orbital differentiation across the phase diagram of plutonium metal
W. H. Brito, Gabriel Kotliar
Abstract
We compare the trends on the strength of electronic correlations across the different phases of elemental Pu focusing on its site and orbital dependence, using a combination of density functional theory (DFT) and dynamical mean-field theory (DMFT) calculations within the vertex corrected one crossing approximation. We find that $\mathrm{Pu}\text{\ensuremath{-}}5f$ states are more correlated in $\ensuremath{\delta}$-Pu, followed by some crystallographic sites in $\ensuremath{\alpha}$ and $\ensuremath{\beta}$ phases. In addition, we observe that $\mathrm{Pu}\text{\ensuremath{-}}5{f}_{5/2}$ and $\mathrm{Pu}\text{\ensuremath{-}}5{f}_{7/2}$ orbital differentiation is a general feature of this material, as is site differentiation in the low-symmetry phases. The $\mathrm{Pu}\text{\ensuremath{-}}5{f}_{5/2}$ states show Fermi liquid like behavior, whereas the $\mathrm{Pu}\text{\ensuremath{-}}5{f}_{7/2}$ states remaining incoherent down to very low temperatures. We correlate the correlation strength in the different phases to their structure and the $\mathrm{Pu}\text{\ensuremath{-}}5f$ occupancy of their crystallographic sites.