Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 5: Correlated Electrons: Spin Systems and Itinerant Magnets – Frustrated Magnets 1 (jointly with MA)
TT 5.9: Vortrag
Montag, 16. März 2015, 11:45–12:00, H 0110
Magnetic order within Kitaev–Heisenberg model — •Dorota Gotfryd1 and Andrzej M. Oles2,3 — 1Institute of Theoretical Physics, Warsaw University, Pasteura 5, PL-02093 Warsaw, Poland — 2Marian Smoluchowski Institute of Physics, Jagiellonian University, prof. S. Łojasiewicza 11, PL-30348 Kraków, Poland — 3Max-Planck-Institut FKF, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
We present the evolution of energy spectra, spin correlation functions and order parameters for Kitaev–Heisenberg (KH) model on a single hexagon within a cluster mean-field approximation introduced in [1] in order to induce the breaking of SU(2) symmetry. The changes of these quantities are used to determine quantum phase transitions within KH model between the antiferromagnetic, stripe and Kitaev phases. In the quest of seeking physically preferred zigzag phase [2] we investigate the modifications of the phase diagram given by: (i) second and third neighbor Heisenberg terms, and (ii) anisotripic Ising-like terms added to KH Hamiltonian. We discuss the stability of this phase and possible implications for honeycomb iridates.
This work is supported by the NCN Project No. 2012/04/A/ST3/00331.
[1] A. F. Albuquerque et al., Phys. Rev. B 84, 024406 (2011).
[2] J. G. Rau et al., Phys. Rev. Lett. 112, 077204 (2014).