Berlin 2018 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 91: Correlated Electrons: Method Development
TT 91.5: Vortrag
Donnerstag, 15. März 2018, 16:00–16:15, H 0104
Charge dynamics of the antiferromagnetically ordered Mott insulator — •Xing-Jie Han1, Yu Liu2,3, Zhi-Yuan Liu4, Xin Li1, Jing Chen1, Hai-Jun Liao1, Zhi-Yuan Xie5, B Normand5, and Tao Xiang1,6 — 1Institute of Physics, Chinese Academy of Sciences — 2LCP, Institute of Applied Physics and Computational Mathematics, Beijing — 3Software Center for High Performance Numerical Simulation, Chinese Academy of Engineering Physics — 4Institute of Theoretical Physics, Chinese Academy of Sciences — 5Department of Physics, Renmin University of China — 6Collaborative Innovation Center of Quantum Matter, Beijing
We introduce a slave-fermion formulation in which to study the charge dynamics of the half-filled Hubbard model on the square lattice. In this description, the charge degrees of freedom are represented by fermionic holons and doublons and the Mott-insulating characteristics of the ground state are the consequence of holon-doublon bound-state formation. The bosonic spin degrees of freedom are described by the antiferromagnetic Heisenberg model. Within this framework and in the self-consistent Born approximation, we perform systematic calculations of the average double occupancy, the electronic density of states, the spectral function and the optical conductivity. Qualitatively, our method reproduces the lower and upper Hubbard bands, the spectral-weight transfer into a coherent quasiparticle band at their lower edges and the renormalisation of the Mott gap, which is associated with holon-doublon binding, due to the interactions of both quasiparticle species with the magnons.