Chiral Antiferromagnetism from Momentum-Space Resonance in a 2D Semiconductor
Abstract
Understanding the principles governing the emergence of chiral quantum phases is a fundamental challenge, not only for uncovering new mechanisms of quantum-state formation but also for realizing giant electronic responses and transport phenomena arising from chirality and topology. While Fermi-surface instabilities in metals can stabilize complex ordered states through multiple competing scattering channels, their microscopic origin is often obscured by the complexity of the underlying electronic structure, limiting the development of general microscopic design principles. Here, we introduce a complementary strategy based on the simplicity of semiconductor band extrema. Using the layered van der Waals semiconductor GdGaI, whose low-energy electronic structure consists of simple electron and hole valleys, we discover the spontaneous emergence of an intertwined chiral triple-q antiferromagnetic state accompanied by a cooperative reconstruction of the electron-hole band edges, beyond the conventional expectation of a single-q ground state. This collective reconstruction generates substantial momentum-space Berry curvature, giving rise to a pronounced spontaneous anomalous Hall effect despite the semiconducting character and negligible net magnetization. Remarkably, this chiral state is realized within an atomically well-defined (≈2a), topologically nontrivial magnetic texture, showing that such collective quantum states can emerge at an exceptionally small length scale from a simple two-dimensional magnetic semiconductor. More broadly, our results introduce a remarkably simple design concept for chiral quantum matter: using simple semiconductor band extrema as building blocks for resonance-like interplay in momentum space, providing a route to Berry curvature, topological transport, and emergent quantum phases.
Related
- Chiral superconductors from parent states with nonuniform Berry curvature: Momentum-space vortices, Bogoliubov-de Gennes topology, and thermal Hall conductivity
- Switchable chiral antiferromagnetism through nonlinear magnetic susceptibility
- A Chiral Superlattice Route to Spin-Split Topological Antiferromagnetism
- Evolution and breakdown of chiral anomaly in Weyl semiconductor tellurium
- Quark orbital angular momentum from chiral symmetry breaking in QCD
BibTeX
@misc{okuma2026chiral,
title = {{Chiral Antiferromagnetism from Momentum-Space Resonance in a 2D Semiconductor}},
author = {R. Okuma and T. Ikenobe and Y. Fujisawa and K. Yamagami and H. C. H. Wu and T. Nakamura and Y. Ihara and H. Ishikawa and H. Suwa and H. Ishizuka and Y. Akagi and T. Kaneko and C. H. Hsu and Y. Obata and N. Tomoda and M. Dronova and K. Nagasawa and H. Saito and D. Ueta and H. Sagayama and J. Yamaura and M. Arita and K. Yogendra and S. Ideta and K. Kindo and T. Nakajima and S. J. Blundell and T. Kondo and K. Shimada and Y. Okamoto and Y. Okada},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.15854},
eprint = {2609.15854},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.15854},
}
RIS
TY - UNPB
TI - Chiral Antiferromagnetism from Momentum-Space Resonance in a 2D Semiconductor
AU - R. Okuma
AU - T. Ikenobe
AU - Y. Fujisawa
AU - K. Yamagami
AU - H. C. H. Wu
AU - T. Nakamura
AU - Y. Ihara
AU - H. Ishikawa
AU - H. Suwa
AU - H. Ishizuka
AU - Y. Akagi
AU - T. Kaneko
AU - C. H. Hsu
AU - Y. Obata
AU - N. Tomoda
AU - M. Dronova
AU - K. Nagasawa
AU - H. Saito
AU - D. Ueta
AU - H. Sagayama
AU - J. Yamaura
AU - M. Arita
AU - K. Yogendra
AU - S. Ideta
AU - K. Kindo
AU - T. Nakajima
AU - S. J. Blundell
AU - T. Kondo
AU - K. Shimada
AU - Y. Okamoto
AU - Y. Okada
PY - 2026
DA - 2026/09/14
PB - arXiv
DO - 10.48550/arxiv.2609.15854
UR - https://arxiv.org/abs/2609.15854
AB - Understanding the principles governing the emergence of chiral quantum phases is a fundamental challenge, not only for uncovering new mechanisms of quantum-state formation but also for realizing giant electronic responses and transport phenomena arising from chirality and topology. While Fermi-surface instabilities in metals can stabilize complex ordered states through multiple competing scattering channels, their microscopic origin is often obscured by the complexity of the underlying electronic structure, limiting the development of general microscopic design principles. Here, we introduce a complementary strategy based on the simplicity of semiconductor band extrema. Using the layered van der Waals semiconductor GdGaI, whose low-energy electronic structure consists of simple electron and hole valleys, we discover the spontaneous emergence of an intertwined chiral triple-q antiferromagnetic state accompanied by a cooperative reconstruction of the electron-hole band edges, beyond the conventional expectation of a single-q ground state. This collective reconstruction generates substantial momentum-space Berry curvature, giving rise to a pronounced spontaneous anomalous Hall effect despite the semiconducting character and negligible net magnetization. Remarkably, this chiral state is realized within an atomically well-defined (≈2a), topologically nontrivial magnetic texture, showing that such collective quantum states can emerge at an exceptionally small length scale from a simple two-dimensional magnetic semiconductor. More broadly, our results introduce a remarkably simple design concept for chiral quantum matter: using simple semiconductor band extrema as building blocks for resonance-like interplay in momentum space, providing a route to Berry curvature, topological transport, and emergent quantum phases.
ER -