Regensburg 2013 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 51: Correlated Electrons: General Theory 1

TT 51.8: Vortrag

Donnerstag, 14. März 2013, 11:30–11:45, H6

Non-perturbative precursors of the Mott-Hubbard transition at the two-particle level — •Thomas Schaefer¹, Georg Rohringer¹, Karsten Held¹, Olle Gunnarsson², Sergio Ciuchi³, Giorgio Sangiovanni⁴, and Alessandro Toschi¹ — ¹Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria — ²Max Planck Institute for Solid State Research, Stuttgart, Germany — ³Universita degli Studi de l’Aquila, L’Aquila, Italy — ⁴Institute of Physics and Astrophysics, University of Würzburg, Würzburg, Germany

Amongst plenty other successes, DMFT is able to cover the Mott-Hubbard metal-to-insulator transition (MIT), which is an intrinsic non-perturbative phenomenon. At the MIT the local spin susceptibility diverges, following Curie’s law in the insulating phase, whereas the local charge susceptibility remains finite at the transition [1]. However, these divergencies are not the only hallmarks of the MIT at the two-particle level. In fact, the first non-perturbative precursors of the MIT can be identified well inside the metallic phase in the frequency structures of the irreducible vertex functions [2,3]. The strong enhancements of the irreducible vertex functions, characterising this precursor, stem from local scattering processes and can be traced up to the limit of high temperatures (i.e. the atomic limit).
[1] A. Georges et al., Rev. Mod. Phys. 68, 13-125 (1996)
G. Rohringer et al., Phys. Rev. B 86, 125114 (2012)
T. Schaefer et al., in preparation (2012)