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arXiv · 2408.07968

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

Wang Yang·Chao Xu·Shicheng Ma·Alberto Nocera·Ian Affleck
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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 $c=1$, 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.

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Wang Yang, Chao Xu, Shicheng Ma, Alberto Nocera, Ian Affleck. 2024-08-15. Left-left-right-right magnetic order in spin-1/2 Kitaev-Heisenberg chain. https://doi.org/10.1103/6ytv-7d16

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