Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Correlated Electrons: Spin Systems and Itinerant Magnets 1
TT 3.2: Vortrag
Montag, 23. März 2009, 10:30–10:45, HSZ 304
DMRG Study of Anisotropic Triangular Heisenberg Lattice — •Andreas Weichselbaum1,2 and Steven R. White2 — 1Ludwig-Maximilians-Universität, Lehrstuhl Jan von Delft, 80333 München — 2University of California, Irvine, CA 92697, USA
The anisotropic antiferromagnetic two-dimensional triangular Heisenberg lattice for spin 1/2 describes certain classes of transition-metal oxides (TMOs) and chalcogenides (TMCs), clearly supported by experimental data. The understanding of the ground state properties of this kind of system from a theoretical point of view, however, has remained an extraordinary challenge. In the model under consideration, quasi-one-dimensional Heisenberg chains of uniform intrachain coupling strength J interact with their neighboring chains via the interchain coupling J′. By varying the anisotropy ratio j ≡ J′/J from j=0 (decoupled Heisenberg chains) to j=1 (uniform triangular lattice with finite Neel order like local magnetization), it was pointed out in previous studies [1] that, indeed, there appears to exist spin liquid properties up to remarkably high values of j of about 0.85. We put these partially conjectured results under scrutiny by applying DMRG on finite systems with cylindrical boundary conditions specifically optimized to reduce finite size effects [2].
[1] S. Yunoki et al., PRB 74, 014408 (2006).
[2] S. R. White et al., PRL 99, 127004 (2007).