Berlin 2018 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 101: Correlated Electrons: Other Materials
TT 101.6: Vortrag
Donnerstag, 15. März 2018, 17:00–17:15, HFT-FT 101
Orbital disproportionation of electronic density is a universal feature of alkali-doped fullerides — •Naoya Iwahara and Liviu Chibotaru — Theory of Nanomaterials Group, University of Leuven, Leuven, Belgium
Alkali-doped fullerides AnC60 show a remarkably wide range of electronic phases in function of A = Li, Na, K, Rb, Cs and the degree of doping, n= 1-5. While the presence of strong electron correlations is well established, recent investigations give also evidence for dynamical Jahn-Teller instability in the insulating and the metallic phase of A3C60 [1, 2]. To reveal the interplay of these interactions in fullerides with even n, we address the electronic phase of A4C60 with accurate many-body calculations within a realistic electronic model including all basic interactions extracted from first principles [3]. We find that the Jahn-Teller instability is always realized in these materials too. More remarkably, in sharp contrast to strongly correlated A3C60, A4C60 displays uncorrelated band-insulating state despite pretty similar interactions present in both fullerides. Our results show that the Jahn-Teller instability and the accompanying orbital disproportionation of electronic density in the degenerate LUMO band is a universal feature of fullerides.