Quasiparticle multiplets and 5f electronic correlation in prototypical plutonium borides

In this paper, we investigate the electronic structures of plutonium borides (PuB x , x = 1, 2, 6, 12) to uncover the fascinating bonding behavior and orbital dependent correlations of 5f valence electrons by using the density functional theory combined with single-site dynamical mean-field method. We not only reproduce the correlated topological insulator of PuB6, but also predict the metallicity in PuB x (x = 1, 2, 12). It is found that the band structure, density of states, hybridization functions all indicate partially itinerant 5f states in PuB x (x = 1, 2, 6, 12). Especially, quasiparticle multiplets induced noteworthy valence state fluctuations implying the mixed-valence behavior of plutonium borides. Moreover, the itinerant degree of freedom for 5f electrons in PuB x (x = 1, 2, 12) is tuned by hybridization strength between 5f states and conduction bands, which is affected by atomic distance in plutonium borides. Lastly, 5f electronic correlations encoded in the electron self-energy functions demonstrate moderate 5f electronic correlations in PuB6 and orbital selective 5f electronic correlations in PuB x (x = 1, 2, 12). Consequently, the understanding of electronic structure and related crystal structure stability shall shed light on exploring novel 5f electrons states and ongoing experiment study.

Automated summary

In this paper, the electronic structures of plutonium borides are investigated using density functional theory combined with single-site dynamical mean-field method. The study reveals the fascinating bonding behavior and orbital dependent correlations of 5f valence electrons in the plutonium borides. The research not only reproduces the correlated topological insulator of PuB6, but also predicts the metallicity in PuB x (x = 1, 2, 12). The understanding of the electronic structure and crystal structure stability of plutonium borides is important for exploring novel 5f electron states and ongoing experimental studies.