Kim, B., Khmelevskyi, S., Mohn, P., & Franchini, C. (2017). Competing magnetic interactions in a spin-½ square lattice: Hidden order in Sr₂VO₄. Physical Review B, 96(18), 1–6. https://doi.org/10.1103/physrevb.96.180405
E134-01 - Forschungsbereich Applied and Computational Physics
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Journal:
Physical Review B
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ISSN:
2469-9950
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Date (published):
8-Nov-2017
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Number of Pages:
6
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Publisher:
AMER PHYSICAL SOC
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Peer reviewed:
Yes
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Abstract:
With decreasing temperature, Sr2VO4 undergoes two structural phase transitions, tetragonal-to-orthorhombicto-tetragonal, without long-range magnetic order. Recent experiments suggest that only at very low temperature,Sr2VO4 might enter a yet-unknown phase with long-range magnetic order, but without orthorhombic distortion.By combining relativistic density functional theory with an extended spin-1/2 compass-Heisenberg model, wefind an antiferromagnetic single-stripe ground state with highly competing exchange interactions, involving a non-negligible interlayer coupling, which places the system at the crossover between the XY-model and Heisenberg-model regimes. Most strikingly, we find a strong two-site "spin-compass" exchange anisotropy which is relieved by the orthorhombic distortion induced by the spin stripe order. Based on these results, we discuss the origin of the hidden-order phase and the possible formation of a spin liquid at low temperatures.
