Evolution from Kitaev to XXZ spin chains via distortion: Application to BaCo2V2O8
Abstract
BaCo2V2O8 is a prototypical spin-orbit-coupled Ising-chain antiferromagnet that provides a unique platform for studying field-induced quantum magnetism. Under a transverse magnetic field, it exhibits unusual magnetic properties, including an anomalous staggered magnetization and a pronounced anisotropy of the critical field with respect to the in-plane field direction. While these phenomena have been attributed phenomenologically to a site-dependent anisotropic g-tensor, a recent microscopic theory has shown that spin-orbit coupling naturally generates bond-dependent Heisenberg, Kitaev, and Γ exchange interactions. Here, we unify these two pictures by extending the microscopic theory to incorporate distortions of the CoO6 octahedra. We show that the distortions not only generate the site-dependent anisotropic g-tensor but also renormalize the staggered exchange interactions through a distortion-induced contribution that partially compensates the Kitaev-derived staggered term. Using point-charge calculations to estimate the g-tensor of BaCo2V2O8, we demonstrate that the strong anisotropy of the critical field originates from the combined effects of the modified exchange interactions and the anisotropic g-tensor. Our work provides a unified microscopic framework for understanding the magnetic anisotropy of spin-orbit-coupled Ising-chain materials.
Related
- Renormalization group analysis for bosonization coefficients in half-odd-integer Kitaev spin chains
- Temperature evolution of spin dynamics in extended Kitaev models within an Abrikosov fermion theory beyond mean field
- One-clean-qubit spectroscopy of simulated Kitaev chains
- Andreev exceptional points in Josephson junctions formed by minimal Kitaev chains
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BibTeX
@misc{richard2026evolution,
title = {{Evolution from Kitaev to XXZ spin chains via distortion: Application to BaCo$_2$V$_2$O$_8$}},
author = {Philip Richard and Mandev Bhullar and Hae-Young Kee},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.01805},
eprint = {2609.01805},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.01805},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Evolution from Kitaev to XXZ spin chains via distortion: Application to BaCo_2V_2O_8
AU - Philip Richard
AU - Mandev Bhullar
AU - Hae-Young Kee
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.01805
UR - https://arxiv.org/abs/2609.01805
AB - BaCo_2V_2O_8 is a prototypical spin-orbit-coupled Ising-chain antiferromagnet that provides a unique platform for studying field-induced quantum magnetism. Under a transverse magnetic field, it exhibits unusual magnetic properties, including an anomalous staggered magnetization and a pronounced anisotropy of the critical field with respect to the in-plane field direction. While these phenomena have been attributed phenomenologically to a site-dependent anisotropic g-tensor, a recent microscopic theory has shown that spin-orbit coupling naturally generates bond-dependent Heisenberg, Kitaev, and Γ exchange interactions. Here, we unify these two pictures by extending the microscopic theory to incorporate distortions of the CoO_6 octahedra. We show that the distortions not only generate the site-dependent anisotropic g-tensor but also renormalize the staggered exchange interactions through a distortion-induced contribution that partially compensates the Kitaev-derived staggered term. Using point-charge calculations to estimate the g-tensor of BaCo_2V_2O_8, we demonstrate that the strong anisotropy of the critical field originates from the combined effects of the modified exchange interactions and the anisotropic g-tensor. Our work provides a unified microscopic framework for understanding the magnetic anisotropy of spin-orbit-coupled Ising-chain materials.
ER -