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arXiv · 2312.15615

Signature of BKT-like spin transport in a quasi-2D antiferromagnet BaNi$_2$V$_2$O$_8$

Kurea Nakagawa·Minoru Kanega·Tomoyuki Yokouchi·Masahiro Sato·Yuki Shiomi
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Abstract

In two-dimensional (2D) spin systems, the augmentation of spin fluctuations gives rise to quasi-long-range order; however, how they manifest in spin transport remains unclear. Here we investigate the spin Seebeck effect (SSE) in a quasi-2D antiferromagnet, BaNi$_2$V$_2$O$_8$, which has been reported to exhibit the Berezinskii-Kosterlitz-Thouless (BKT) transition owing to its distinct 2D nature. We found that the SSE in Pt / BaNi$_2$V$_2$O$_8$ persists well above the N\'eel temperature, significantly different from the behavior of 3D ordered magnets. Our numerical analysis for a 2D microscopic spin model supports the hypothesis that the observed SSE is linked to strong magnetic correlations in the BKT-like phase.

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Kurea Nakagawa, Minoru Kanega, Tomoyuki Yokouchi, Masahiro Sato, Yuki Shiomi. 2023-12-25. Signature of BKT-like spin transport in a quasi-2D antiferromagnet BaNi$_2$V$_2$O$_8$. https://doi.org/10.1103/physrevmaterials.9.l011401

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