Spin-Polarized Weyl Fermions and Unconventional Spin Transport
Abstract
Large and electrically controllable spin splitting in nonmagnetic materials is highly desirable for condensed-matter physics and spintronics, enabling strongly spin-polarized quasiparticles and unconventional spin transport as well as their electrical control. Here, we establish a general framework for critical spin-polarized Weyl fermions in two-dimensional (2D) nonmagnetic systems. We predict the α-Bi-like Group-V puckered-layer family of 2D ferroelectrics as a material platform combining critical spin-Weyl fermions, giant spin splitting, and electrically switchable nonlinear and spin transport. Our calculations reveal exchange-scale spin splitting induced by spin-orbit coupling and a p-wave spin texture in the BiAs monolayer. Moreover, BiAs hosts four critical spin-Weyl points, each formed within a single-spin channel. The nearly quantized ⟨ Sz⟩ is protected by an emergent Sz-conservation symmetry in the low-energy limit. The spin-Weyl cones also give rise to unconventional spin-transport phenomena, including a purely out-of-plane Edelstein response and a pronounced spin Nernst effect. Ferroelectric reversal further enables electrical switching of the p-wave spin texture and inversion-odd responses, while the tunability of these properties through composition, strain, and magnetic field is also systematically demonstrated across the entire family. These results establish both a general nonmagnetic framework and a promising material platform for exploring critical spin-Weyl physics, nonlinear Hall phenomena, and unconventional spin transport.
Related
- Unconventional SOC-activated Altermagnetic Spin Splitting and Half-Angle Locking of Spin Transport
- Application of Grassmannian techniques and Kubo formula to the transport of fermions in a two-dimensional frustrated spin medium
- Transducing quantum-spin-ice correlations into Weyl Fermi-arc transport at a synthetic Kondo lattice interface
- Global anomalies in sigma models with Majorana-Weyl fermions
- The Standard Model on a finite bosonic lattice with continuum Weyl fermions
BibTeX
@misc{liang2026spinpolarized,
title = {{Spin-Polarized Weyl Fermions and Unconventional Spin Transport}},
author = {Chenhao Liang and Haohao Sheng and Sheng Zhang and Zhong Fang and Hongming Weng and Zhijun Wang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.39604},
eprint = {2610.39604},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.39604},
}
RIS
TY - UNPB
TI - Spin-Polarized Weyl Fermions and Unconventional Spin Transport
AU - Chenhao Liang
AU - Haohao Sheng
AU - Sheng Zhang
AU - Zhong Fang
AU - Hongming Weng
AU - Zhijun Wang
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2610.39604
UR - https://arxiv.org/abs/2610.39604
AB - Large and electrically controllable spin splitting in nonmagnetic materials is highly desirable for condensed-matter physics and spintronics, enabling strongly spin-polarized quasiparticles and unconventional spin transport as well as their electrical control. Here, we establish a general framework for critical spin-polarized Weyl fermions in two-dimensional (2D) nonmagnetic systems. We predict the α-Bi-like Group-V puckered-layer family of 2D ferroelectrics as a material platform combining critical spin-Weyl fermions, giant spin splitting, and electrically switchable nonlinear and spin transport. Our calculations reveal exchange-scale spin splitting induced by spin-orbit coupling and a p-wave spin texture in the BiAs monolayer. Moreover, BiAs hosts four critical spin-Weyl points, each formed within a single-spin channel. The nearly quantized ⟨ S_z⟩ is protected by an emergent S_z-conservation symmetry in the low-energy limit. The spin-Weyl cones also give rise to unconventional spin-transport phenomena, including a purely out-of-plane Edelstein response and a pronounced spin Nernst effect. Ferroelectric reversal further enables electrical switching of the p-wave spin texture and inversion-odd responses, while the tunability of these properties through composition, strain, and magnetic field is also systematically demonstrated across the entire family. These results establish both a general nonmagnetic framework and a promising material platform for exploring critical spin-Weyl physics, nonlinear Hall phenomena, and unconventional spin transport.
ER -