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arXiv · 2608.24463

Anomalous magnetocaloric effects in the quasi-one-dimensional antiferromagnet BaCo$_2$V$_2$O$_8$

Jiahao Yang·Chao Dong·Xinlong Shi·Zhuo Wang·Tiantian Li·Liusuo Wu·Junfeng Wang·Zhangzhen He·Liang Li·Yongkang Luo·Jianda Wu
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Abstract

We investigate the transverse-field thermodynamics of the quasi-one-dimensional Ising-like antiferromagnet BaCo$_2$V$_2$O$_8$, whose tilted screw-chain geometry and anisotropic Land\'e $g$ tensor generate spatially modulated Zeeman couplings. Angle-resolved magnetocaloric-effect (MCE) measurements reveal a high-field temperature minimum near the transverse-field Ising critical field for $H\parallel[110]$ that persists and shifts only weakly upon field rotation. Tensor-network calculations show that the rotation-induced staggered transverse field rapidly lowers the Ising critical field and that the magnetic Gr\"uneisen ratio changes sign near the high-field temperature minimum, consistent with experiment. Our results establish that a dominant MCE response can persist away from the Ising critical region, suggesting a route to magnetic cooling by tailoring anisotropic Zeeman-coupling configurations in quantum magnets.

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Jiahao Yang, Chao Dong, Xinlong Shi, Zhuo Wang, Tiantian Li, Liusuo Wu, Junfeng Wang, Zhangzhen He, Liang Li, Yongkang Luo, Jianda Wu. 2026-08-25. Anomalous magnetocaloric effects in the quasi-one-dimensional antiferromagnet BaCo$_2$V$_2$O$_8$. https://arxiv.org/abs/2608.24463

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