Berlin 2008 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 28: Correlated Electrons: Metal-Insulator Transition 1
TT 28.3: Vortrag
Donnerstag, 28. Februar 2008, 10:00–10:15, H 2053
Optical conductivity and specific heat anomalies in the proximity of the Mott-Hubbard transition — •Alessandro Toschi1, Massimo Capone2,3, Claudio Castellani3, and Karsten Held1 — 1Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany — 2ISC-CNR, Via dei Taurini 19, I-00185 Roma, Italy — 3SMC, CNR-INFM and Dipartimento di Fisica, Università di Roma ‘La Sapienza’, Piazzale Aldo Moro 2, I-00185 Roma, Italy
A landmark of electronic correlations is the strong renormalization of the quasiparticle peak in the spectral function, and, as it has been recently demonstrated [1], the appearance of kinks in the self-energy at low frequency. As a consequence, strong renormalization of the Drude peak, of the temperature dependence of the optical sum rules and of the specific heat can be expected in the vicinity of the Mott-Hubbard transition. Indeed similar features have been observed in cuprates and, more generally, in transition metal oxides. DMFT calculations, using exact Diagonalization as an impurity solver and a large number of sites in the electronic bath, allow us to perform a detailed comparison with experiments. Our calculations unveil the existence of an anomalous deviation from Fermi-liquid-behavior at temperatures much lower than expected. Taking this deviation into account is important for a correct interpretation of the experimental data.
[1] K. Byczuk, M. Kollar, K. Held, Y.-F. Yang, I.A. Nekrasov, Th. Pruschke, and D. Vollhardt, Nature Physics 3, 168 (2007).
[2] A. Toschi and M. Capone, cond-mat/0708.3475.
[3] A. Toschi, M. Capone, C. Castellani, and K. Held in preparation.