Pressure-induced PT Symmetry Breaking in LaMnSi

Takuya Aoyama; Hikaru Taneoka; Takemi Yamada; Hiroshi Tanida; Kenya Ohgushi

Pressure-induced PT Symmetry Breaking in LaMnSi

Strongly Correlated Electrons 2026-07-08 v1

Authors: Takuya Aoyama , Hikaru Taneoka , Takemi Yamada , Hiroshi Tanida , Kenya Ohgushi

Abstract

We investigate the magnetotransport properties of the antiferromagnetic metal LaMnSi, in which the collinear magnetic order breaks both spatial inversion (P) and time-reversal (T) symmetry yet preserves their combined PT symmetry. High pressure is found to suppress this PT-symmetric antiferromagnetic phase, inducing a transition into a PT-broken state characterized by a large anomalous Hall effect. Based on symmetry analysis, we propose a candidate magnetic structure for the high-pressure phase. Subsequent band calculations for this structure reveal the emergence of band splitting and orbital-dependent spin polarization. Our results establish LaMnSi as an ideal platform for controlling PT symmetry breaking via external parameters.

Keywords

PT symmetry breaking antiferromagnetic metal LaMnSi anomalous Hall effect high pressure magnetotransport band structure

Cite

@article{arxiv.2607.07310,
  title  = {Pressure-induced PT Symmetry Breaking in LaMnSi},
  author = {Takuya Aoyama and Hikaru Taneoka and Takemi Yamada and Hiroshi Tanida and Kenya Ohgushi},
  journal= {arXiv preprint arXiv:2607.07310},
  year   = {2026}
}