Orientation-Dependent Universality of Spin-Transport Fluctuations in Two-Dimensional Altermagnets
Abstract
Universal conductance fluctuations are conventionally organized by symmetry class, but crystalline anisotropy introduces additional structure in spin transport. Here we demonstrate orientation-dependent universal spin-transport fluctuations in disordered two-dimensional d-wave altermagnets without spin-orbit coupling. Rotating the altermagnetic orientation changes both longitudinal spin-conductance and transverse spin-Hall conductance fluctuations, while each conserved-spin sector remains in class AI. Altermagnetic orientation controls both the fluctuation amplitudes and the development of disorder-insensitive plateaus. These plateaus become flatter and less sensitive to the altermagnetic strength over the studied parameter ranges as the orientation approaches 45∘, with representative fluctuation amplitudes of approximately $0.60e/(4π)$ for the longitudinal spin conductance and 0.40 e/(4π) for the spin-Hall conductance. The longitudinal fluctuation amplitude correlates strongly with anisotropy of the clean-band Fermi-velocity tensor. Spin-sector covariances explain how the conserved channels combine into total fluctuations. Our results extend anisotropy-sensitive universal-fluctuation physics to conserved-spin altermagnetic transport and establish crystalline orientation as a control parameter within a fixed symmetry class.
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BibTeX
@misc{zhang2026orientationdependent,
title = {{Orientation-Dependent Universality of Spin-Transport Fluctuations in Two-Dimensional Altermagnets}},
author = {Yihan Zhang and Zheng Qin and Donghui Xu and Junjie Zeng and Zhen Ning and Rui Wang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.19793},
eprint = {2610.19793},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.19793},
}
RIS
TY - UNPB
TI - Orientation-Dependent Universality of Spin-Transport Fluctuations in Two-Dimensional Altermagnets
AU - Yihan Zhang
AU - Zheng Qin
AU - Donghui Xu
AU - Junjie Zeng
AU - Zhen Ning
AU - Rui Wang
PY - 2026
DA - 2026/10/20
PB - arXiv
DO - 10.48550/arxiv.2610.19793
UR - https://arxiv.org/abs/2610.19793
AB - Universal conductance fluctuations are conventionally organized by symmetry class, but crystalline anisotropy introduces additional structure in spin transport. Here we demonstrate orientation-dependent universal spin-transport fluctuations in disordered two-dimensional d-wave altermagnets without spin-orbit coupling. Rotating the altermagnetic orientation changes both longitudinal spin-conductance and transverse spin-Hall conductance fluctuations, while each conserved-spin sector remains in class AI. Altermagnetic orientation controls both the fluctuation amplitudes and the development of disorder-insensitive plateaus. These plateaus become flatter and less sensitive to the altermagnetic strength over the studied parameter ranges as the orientation approaches 45^∘, with representative fluctuation amplitudes of approximately $0.60e/(4π)$ for the longitudinal spin conductance and 0.40 e/(4π) for the spin-Hall conductance. The longitudinal fluctuation amplitude correlates strongly with anisotropy of the clean-band Fermi-velocity tensor. Spin-sector covariances explain how the conserved channels combine into total fluctuations. Our results extend anisotropy-sensitive universal-fluctuation physics to conserved-spin altermagnetic transport and establish crystalline orientation as a control parameter within a fixed symmetry class.
ER -