Plutonium Hexaboride is a Correlated Topological Insulator

We predict that plutonium hexaboride (PuB6) is a strongly correlated topological insulator, with Pu in an intermediate valence state of Pu2.7+. Within the combination of dynamical mean field theory and density functional theory, we show that PuB6 is an insulator in the bulk, with nontrivial Z(2) topological invariants. Its metallic surface states have a large Fermi pocket at the (X) over bar point and the Dirac cones inside the bulk derived electronic states, causing a large surface thermal conductivity. PuB6 has also a very high melting temperature; therefore, it has ideal solid state properties for a nuclear fuel material.