Resolving the Magnetic Ground-State Controversy in RuO2 through A Flat Magnetic Energy Landscape
Abstract
Rutile RuO2 is a prominent candidate for altermagnetism, yet its magnetic ground state remains highly controversial, with experiments reporting either a nonmagnetic state or altermagnetic order. Here, we develop a generalized environment-dependent spin-lattice framework that unifies localized Heisenberg exchange, itinerant Stoner magnetism via Landau spin fluctuations, and spin-orbit-coupling-mediated spin-lattice interactions. Parameterized from a high-throughput first-principles database using machine-learning and solved by large-scale Monte Carlo simulations, the framework reveals an exceptionally flat magnetic energy landscape in RuO2, where the nonmagnetic state lies nearly degenerate with multiple altermagnetic configurations. We find that material perturbations, exemplified by intrinsic defects, select distinct magnetic ground states primarily by modifying the localized Heisenberg exchange, with perturbation-induced itinerant Stoner polarization provides an essential secondary contribution. Spin-orbit coupling controls the orientation and stability of the Néel vector, but does not determine the emergence of long-range magnetic order. These results provide a unified explanation for the conflicting experimental observations and establish a general microscopic framework for understanding how material perturbations select competing magnetic ground states in systems with nearly flat magnetic energy landscapes.
Related
- The bixbyite framework as a platform for frustrated noncollinear magnetism: resolving the magnetic ground state of β-Fe2O3
- Resolving the interfacial mechanical landscape of monolayer NbSe2 grown by confined epitaxy
- Resolving magnetic order and dynamics with polarized neutron scattering: a practical guide to longitudinal polarization analysis
- Origin of the magnetic ground state of Tb2Ir2O7
- Comment on "Long-range magnetic fields in the ground state of the Standard Model plasma"
BibTeX
@misc{liang2026resolving,
title = {{Resolving the Magnetic Ground-State Controversy in RuO2 through A Flat Magnetic Energy Landscape}},
author = {Tianxiao Liang and Fanhan Kong and Jijun Zhao and Xue Jiang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.03274},
eprint = {2609.03274},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.03274},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Resolving the Magnetic Ground-State Controversy in RuO2 through A Flat Magnetic Energy Landscape
AU - Tianxiao Liang
AU - Fanhan Kong
AU - Jijun Zhao
AU - Xue Jiang
PY - 2026
DA - 2026/09/03
PB - arXiv
DO - 10.48550/arxiv.2609.03274
UR - https://arxiv.org/abs/2609.03274
AB - Rutile RuO2 is a prominent candidate for altermagnetism, yet its magnetic ground state remains highly controversial, with experiments reporting either a nonmagnetic state or altermagnetic order. Here, we develop a generalized environment-dependent spin-lattice framework that unifies localized Heisenberg exchange, itinerant Stoner magnetism via Landau spin fluctuations, and spin-orbit-coupling-mediated spin-lattice interactions. Parameterized from a high-throughput first-principles database using machine-learning and solved by large-scale Monte Carlo simulations, the framework reveals an exceptionally flat magnetic energy landscape in RuO2, where the nonmagnetic state lies nearly degenerate with multiple altermagnetic configurations. We find that material perturbations, exemplified by intrinsic defects, select distinct magnetic ground states primarily by modifying the localized Heisenberg exchange, with perturbation-induced itinerant Stoner polarization provides an essential secondary contribution. Spin-orbit coupling controls the orientation and stability of the Néel vector, but does not determine the emergence of long-range magnetic order. These results provide a unified explanation for the conflicting experimental observations and establish a general microscopic framework for understanding how material perturbations select competing magnetic ground states in systems with nearly flat magnetic energy landscapes.
ER -