1301.3713 (A. B. Shick et al.)

Unified character of correlation effects in unconventional Pu-based
superconductors and δ-Pu    [PDF]

A. B. Shick, J. Kolorenc, J. Rusz, P. M. Oppeneer, A. I. Lichtenstein, M. I. Katsnelson, R. Caciuffo

Electronic structure calculations combining the local-density approximation with an exact diagonalization of the Anderson impurity model show an intermediate 5f^5-5f^6-valence ground state and delocalization of the 5f^5 multiplet of the Pu atom 5f-shell in PuCoIn_5, PuCoGa_5, and \delta-Pu. The 5f-local magnetic moment is compensated by a moment formed in the surrounding cloud of conduction electrons. For PuCoGa_5 and \delta-Pu the compensation is complete and the Anderson impurity ground state is a singlet. For PuCoIn_5 the compensation is partial and the Pu ground state is magnetic. We suggest that the unconventional d-wave superconductivity is likely mediated by the 5f-states antiferromagnetic fluctuations in PuCoIn_5, and by valence fluctuations in PuCoGa_5.

View original: http://arxiv.org/abs/1301.3713