Spontaneous Circular Dichroism and Memory Effect from Surface Defects in Altermagnetic MnTe
Abstract
Altermagnetism has emerged as a new class of magnetism with vanishing magnetization and macroscopic time reversal symmetry breaking. Hexagonal MnTe is a g-wave altermagnet with a 307 K Néel temperature, large spin splitting, and an anomalous Hall effect. However, the relationship between altermagnetism and the anomalous Hall effect in MnTe remains debated. Here, using optical magnetic circular dichroism, we observe hysteresis and a memory effect in a MnTe bulk crystal below 250 K. No hysteresis is seen after polishing the bulk crystal and in thin films. We conclude that the hysteresis in magnetic circular dichroism in the bulk crystal is from surface defects. The similar temperature dependence and a sign change between circular dichroism and the anomalous Hall effect indicate that the origin of the anomalous Hall effect in transport is likely not intrinsic.
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BibTeX
@misc{mead2026spontaneous,
title = {{Spontaneous Circular Dichroism and Memory Effect from Surface Defects in Altermagnetic MnTe}},
author = {Benjamin F. Mead and Isaiah Gray and Seng Huat Lee and Michael Chilcote and Zi-Jie Yan and Sijie Xu and Aparna Jayakumar and Emilia Morosan and Jörn W. F. Venderbos and Cui-Zu Chang and Zhiqiang Mao and Pengcheng Dai and Matthew Brahlek and Liang Wu},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.41797},
eprint = {2610.41797},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.41797},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Spontaneous Circular Dichroism and Memory Effect from Surface Defects in Altermagnetic MnTe
AU - Benjamin F. Mead
AU - Isaiah Gray
AU - Seng Huat Lee
AU - Michael Chilcote
AU - Zi-Jie Yan
AU - Sijie Xu
AU - Aparna Jayakumar
AU - Emilia Morosan
AU - Jörn W. F. Venderbos
AU - Cui-Zu Chang
AU - Zhiqiang Mao
AU - Pengcheng Dai
AU - Matthew Brahlek
AU - Liang Wu
PY - 2026
DA - 2026/10/30
PB - arXiv
DO - 10.48550/arxiv.2610.41797
UR - https://arxiv.org/abs/2610.41797
AB - Altermagnetism has emerged as a new class of magnetism with vanishing magnetization and macroscopic time reversal symmetry breaking. Hexagonal MnTe is a g-wave altermagnet with a 307 K Néel temperature, large spin splitting, and an anomalous Hall effect. However, the relationship between altermagnetism and the anomalous Hall effect in MnTe remains debated. Here, using optical magnetic circular dichroism, we observe hysteresis and a memory effect in a MnTe bulk crystal below 250 K. No hysteresis is seen after polishing the bulk crystal and in thin films. We conclude that the hysteresis in magnetic circular dichroism in the bulk crystal is from surface defects. The similar temperature dependence and a sign change between circular dichroism and the anomalous Hall effect indicate that the origin of the anomalous Hall effect in transport is likely not intrinsic.
ER -