@article{RousochatzakisReutherThomaleetal.2015,
  author    = {Rousochatzakis, Ioannis and Reuther, Johannes and Thomale, Ronny and Rachel, Stephan and Perkins, N. B.},
  title     = {Phase Diagram and Quantum Order by Disorder in the Kitaev K\(_1\) - K\(_2\) Honeycomb Magnet},
  series = {Physical Review X},
  volume    = {5},
  journal   = {Physical Review X},
  number    = {041035},
  doi       = {10.1103/PhysRevX.5.041035},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137235},
  year      = {2015},
  abstract  = {We show that the topological Kitaev spin liquid on the honeycomb lattice is extremely fragile against the second-neighbor Kitaev coupling K\(_2\), which has recently been shown to be the dominant perturbation away from the nearest-neighbor model in iridate Na\(_2\)IrO\(_3\), and may also play a role in \(\alpha\)-RuCl\(_3\) and Li\(_2\)IrO\(_3\). This coupling naturally explains the zigzag ordering (without introducing unrealistically large longer-range Heisenberg exchange terms) and the special entanglement between real and spin space observed recently in Na\(_2\)IrO\(_3\). Moreover, the minimal K\(_1\) - K\(_2\) model that we present here holds the unique property that the classical and quantum phase diagrams and their respective order-by-disorder mechanisms are qualitatively different due to the fundamentally different symmetries of the classical and quantum counterparts.},
  language  = {en}
}