Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 63: Focussed session: Frontiers of electronic structure theory: Strong correlations from first principles IV (jointly with TT)

O 63.5: Vortrag

Donnerstag, 29. März 2012, 11:45–12:00, HE 101

Electron correlation effects in americium metal under pressure — •Alexander Shick^1,2, Jindrich Kolorenc², and Roberto Caciuffo¹ — ¹European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe — ²Institute of Physics ASCR, Prague

Evolution of the electronic structure of elemental americium due to the lattice compression is investigated. We make use of a version of the LDA+DMFT method based on the "exact diagonalization" of the multi-orbital Anderson impurity Hamiltonian with the full Coulomb interaction matrix and the spin-orbit coupling [1]. Also, we include the charge density self-consistency [2]. We observe only a relatively minor modifications of the electronic structure with compression, which appears to be in accord with the RXES and XANES spectra at the L₃ edge that were recently determined experimentally [3]. Neither these experiments nor our calculations support the earlier theoretical proposal that the f-electron occupation should increase with compression, leading eventually to a mixed-valence (5f⁶ + 5f⁷) behavior [4].

[1] A. B. Shick, J. Kolorenc, V. Janis, A. I. Lichtenstein, Phys. Rev. B 84, 113112 (2011). [2] A. B. Shick, J. Kolorenc, L. Havela, A. I. Lichtenstein, Phys. Rev. B 80, 085106 (2009). [3] S. Heathman, J.-P. Rueff, L. Simonelli, M. A. Denecke, J.-C. Griveau, R. Caciuffo, G. H. Lander, Phys. Rev. B 82, 201103 (2010). [4] S. Y. Savrasov, K. Haule, G. Kotliar, Phys. Rev. Lett. 96, 036404 (2006).