English

Left-left-right-right magnetic order in spin-1/2 Kitaev-Heisenberg chain

Strongly Correlated Electrons 2025-07-08 v2

Abstract

In this work, we perform a combination of analytical and numerical studies on the phase diagram of the spin-1/2 Kitaev-Heisenberg chain in the region of negative Kitaev and positive Heisenberg couplings. Apart from the antiferromagnetic phase, we find a magnetically ordered phase with left-left-right-right order and a gapless phase with central charge value c=1c=1, resolving the existing contradictory results in literature regarding this parameter region. In particular, the origin of the left-left-right-right order is clarified based on a perturbative Luttinger liquid analysis. The left-left-right-right phase is further shown to persist in the Kitaev-Heisenberg-Gamma model when a small nonzero Gamma interaction is introduced. Using a coupled-chain method, we also demonstrate that the one-dimensional (1D) left-left-right-right order gives a quasi-1D explanation for the 2D stripy order of the same model on the honeycomb lattice.

Keywords

Cite

@article{arxiv.2408.07968,
  title  = {Left-left-right-right magnetic order in spin-1/2 Kitaev-Heisenberg chain},
  author = {Wang Yang and Chao Xu and Shicheng Ma and Alberto Nocera and Ian Affleck},
  journal= {arXiv preprint arXiv:2408.07968},
  year   = {2025}
}

Comments

25 pages, 12 figures