Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 65: Low-Dimensional Systems: 1D – Theory
TT 65.5: Vortrag
Mittwoch, 18. März 2015, 16:15–16:30, H 0104
Spin-charge-separated quasi-particles in 1D quantum fluids — •Imke Schneider1, Rodrigo G. Pereira2, and Fabian H. Essler3 — 1Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany — 2Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, C.P. 369, Sao Carlos, SP, 13560-970, Brazil — 3The Rudolf Peierls Centre for Theoretical Physics, Oxford University, Oxford OX1 3NP, United Kingdom
Interacting one-dimensional quantum fluids are well-studied examples of systems in which the Fermi liquid paradigm of electron-like quasi-particles is known to break down. Instead, Luttinger liquid theory predicts separate spin- and charge-density waves - bosonic in nature - as the fundamental collective excitations at low energies.
Recently, the idea of fermionic quasi-particles for 1D quantum fluids was revived by the interest in dynamics beyond the Luttinger liquid paradigm. Here we propose a constructive approach to introduce fermionic quasi-particles for two-component Luttinger liquids. We point out that a model with weakly interacting fermionic quasi-particles at low energies - a good starting point for the universal theory of nonlinear Luttinger liquids - is a double Luther-Emery Point which can only be reached by fine tuning of strong interactions. Using density matrix renormalization group(DMRG) methods, we search for a lattice realization of this point in an extended Hubbard model with longer-range density-density and spin exchange interactions.