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TT: Fachverband Tiefe Temperaturen
TT 4: Low-Dimensional Systems: 1D - Theory
TT 4.9: Vortrag
Montag, 31. März 2014, 11:45–12:00, HSZ 201
Dynamical response functions in the 1D Hubbard model — •Imke Schneider1, Rodrigo G. Pereira2, and Fabian H. Essler1 — 1The Rudolf Peierls Centre for Theoretical Physics, Oxford University, Oxford OX1 3NP, United Kingdom — 2Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, C.P. 369, Sao Carlos, SP, 13560-970, Brazil
Dynamical response functions are of particular interest in view of experimental applications such as momentum resolved tunneling in quantum wires. However, in recent works it was demonstrated that neglecting curvature in the generic dispersion in 1D - resulting in Luttinger liquid theory - leads to incorrect results for singularities in dynamical responses. Using a mapping to a Luttinger liquid with an additional high frequency mobile impurity and taking the leading irrelevant operators into account nonperturbatively it is possible to determine the exact threshold singularities.
We present a constructive derivation of such a mobile impurity model for the 1D Hubbard model. Crucially, the Luther-Emery point for both charge and spin fermions constitutes the good starting point for a weak coupling expansion. As an application we discuss the zero temperature optical conductivity of the 1D Hubbard model in the gapless phase.