Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

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 Capone^2,3, 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.