Electronic band-structure hybridization in the heavy-fermion superconductorUPt3

Many physical properties, such as electrical resistivity and specific heat, of ${\mathrm{UPt}}_3$ are different from the other two heavy-fermion superconductors, ${\mathrm{UBe}}_{13}$ and ${\mathrm{CeCu}}_2$ ${\mathrm{Si}}_2$. The electronic structure of ${\mathrm{UPt}}_3$ also differs from the other two materials because of the presence of the platinum d band, which is close in energy to the uranium 5f band that is responsible for the exotic heavy-fermion ground state. In this paper various contributions to linear muffin-tin orbital atomic-sphere approximation electronic band-structure calculations are examined to show that platinum p hybridization is the dominant platinum hybridization mediating the formation of the uranium 5f band. The main effect of uranium 5f and platinum 5d hybridization is instead to induce platinum d character at the Fermi energy that would otherwise be absent, while having little effect on the uranium 5f band itself. Any experiment, such as soft-x-ray emission, resonant photoemission, or nuclear magnetic resonance that can probe this platinum d character could yield an important confirmation of itinerant uranium f electrons.