Regensburg 2004 – scientific programme
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TT: Tiefe Temperaturen
TT 28: FV-internes Symposium ”Theoretical Modeling of Materials with Correlated Electrons”
TT 28.8: Fachvortrag
Thursday, March 11, 2004, 17:20–17:45, H20
The orbital state and magnetic properties of LiV2O4: Recent insight from LDA+DMFT — •Th. Pruschke — Institute for Theoretical Physics, University of Goettingen, D-37077 Goettingen
LiV2O4 is considered to be the first system showing heavy fermion physics without f electrons. This behaviour is even more surprising if one takes into account that the average occupancy of the Vanadium d-states is 1.5 electrons/V, i.e. the system seems to be rather in the mixed-valence than in the classical Kondo regime typically required for heavy-fermions. Within the framework of DMFT+LDA we show that this part of the puzzle can be resolved in a rather surprising manner, namely by localizing one of the d-electrons in the non-degenerate A1g level of the t2g manifold, while 0.5 electrons/V in the twofold degenerate Eg level remain itinerant. The existence of precisley one localized and 0.5 delocalized electrons per Vanadium leads to very specific theoretical predictions about the magnetic properties of LiV2O4, which can be compared to experiment. In particular, the effective magnetic moment deduced from the high-temperature Curie behavior and inelastic, spin-polarized neutron scattering support our conjecture.