Regensburg 2002 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 22: Postersitzung III: Syst. korr. Elektr.: Theorie II (1-15), Metall-Isol.- und Phasenüberg
änge (16-33), SL: Massivmat., Bandl., Pinning, Vortexdyn., Transport, Korngr. (34-43), Niedrigdim. Syst., Magnetotransport (44-63)

TT 22.11: Poster

Donnerstag, 14. März 2002, 14:00–17:30, A

LDA+DMFT investigation of the electronic properties of LiV₂O₄ — •Igor Nekrasov^1,2, Zlata Pchelkina^1,2, Thomas Pruschke¹, Georg Keller¹, Vladimir Anisimov², and Dieter Vollhardt¹ — ¹Theoretische Physik III, Elektronische Korrelationen und Magnetismus, Universität Augsburg, 86135 Augsburg — ²Institute of Metal Physics, Ekaterinburg GSP-170, Russia

LiV₂O₄ has on average 1.5 d-electrons per site in the t_2g subband, which is further split into A_1g and E_g bands. Normally, such a system should be a valence fluctuator. However, recent experiments indicate that this compound rather behaves like a heavy Fermion system [1]. A theoretical explanation based on an LDA+U calculation was proposed by Anisimov et al. [2]. Here we present a full LDA+DMFT study of the electronic properties of LiV₂O₄. Due to the electronic correlations the A_1g state is localized and half-filled. Its coupling to the 1/8-filled E_g band leads to a low-energy scale consistent with the observed enhanced Sommerfeld coefficient. Strong ferromagnetic correlations at high temperature may explain the neutron scattering data around T=100K [3].

[1] S. Kondo et al., Phys. Rev. Lett. 78, 3729(1997); A.V. Mahajan et al., Phys. Rev. B57, 8890(1998).

[2] V.I. Anisimov et al., Phys. Rev. Lett. 83, 364(1999).

[3] A. Krimmel et al., Phys. Rev. Lett. 82, 2919(1999).