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TT: Tiefe Temperaturen

TT 31: Correlated Electrons: Metal Insulator Transition - Part 2

TT 31.10: Talk

Thursday, March 30, 2006, 16:30–16:45, HSZ 301

Signature of collective excitations close to the metal-to-insulator transition — •Götz Uhrig¹, Carsten Raas¹, and Michal Karski² — ¹FR 7.1, Geb. E2.6, Universität des Saarlandes, D-66123 Saarbrücken — ²Insitut für Angewandte Physik, Universität Bonn, D-53115 Bonn

A high-resolution calculation of the dynamical mean-field equations for the half-filled Hubbard model reveals a clear signature of collective excitations close to the metal-to-insulator transition. This calculation has become possible by current advances in dynamical density-matrix renormalization. The effect of collective excitations is seen as sharp peaks at the inner edges of the Hubbard bands. These peaks evidence a strong interaction between charge and collective degrees of freedom. The corresponding susceptibilities display signatures of the involved collective modes.