Crystal-surface polarity enables nonreciprocal transport in a centrosymmetric kagome magnet
Abstract
Every crystal surface breaks inversion symmetry even when the bulk is centrosymmetric, creating an intrinsic boundary polarity (P). Here we show that this polarity enables zero-field nonreciprocal transport in the centrosymmetric kagome magnets TbMn6Sn6−xInx. In symmetric TbMn6Sn4.4In1.6 microdevices, opposing side surfaces exhibit second-harmonic longitudinal resistances of comparable magnitude and opposite sign. Reversing the spontaneous magnetization (M) reverses both signals, whereas rotating M so that the toroidal moment P × M has no component along the current suppresses the response. In pristine TbMn6Sn6, the signal switches off across the spin-reorientation transition, providing a chemically ordered control of the same symmetry relation. Spatial potential mapping indicates that the nonlinear boundary contribution is distinct from the bulk linear conduction. Spin-orbit-coupled surface states associated with topological bands may enhance the effect. Crystal-surface polarity therefore offers a broadly applicable route to zero-field rectification in centrosymmetric magnetic conductors around room temperature.
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BibTeX
@misc{yamaguchi2026crystalsurface,
title = {{Crystal-surface polarity enables nonreciprocal transport in a centrosymmetric kagome magnet}},
author = {Daiki Yamaguchi and Max T. Birch and Hibiki Onodera and Akiko Kikkawa and Naoto Nagaosa and Yoshinori Tokura},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.34312},
eprint = {2610.34312},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.34312},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Crystal-surface polarity enables nonreciprocal transport in a centrosymmetric kagome magnet
AU - Daiki Yamaguchi
AU - Max T. Birch
AU - Hibiki Onodera
AU - Akiko Kikkawa
AU - Naoto Nagaosa
AU - Yoshinori Tokura
PY - 2026
DA - 2026/10/25
PB - arXiv
DO - 10.48550/arxiv.2610.34312
UR - https://arxiv.org/abs/2610.34312
AB - Every crystal surface breaks inversion symmetry even when the bulk is centrosymmetric, creating an intrinsic boundary polarity (P). Here we show that this polarity enables zero-field nonreciprocal transport in the centrosymmetric kagome magnets TbMn_6Sn_6−xIn_x. In symmetric TbMn_6Sn_4.4In_1.6 microdevices, opposing side surfaces exhibit second-harmonic longitudinal resistances of comparable magnitude and opposite sign. Reversing the spontaneous magnetization (M) reverses both signals, whereas rotating M so that the toroidal moment P × M has no component along the current suppresses the response. In pristine TbMn_6Sn_6, the signal switches off across the spin-reorientation transition, providing a chemically ordered control of the same symmetry relation. Spatial potential mapping indicates that the nonlinear boundary contribution is distinct from the bulk linear conduction. Spin-orbit-coupled surface states associated with topological bands may enhance the effect. Crystal-surface polarity therefore offers a broadly applicable route to zero-field rectification in centrosymmetric magnetic conductors around room temperature.
ER -